refactor(routes): move compare domain into routes/compare/ subpackage (#5660)

Slice 2i of the route-domain reorganization (#4082/#4071). Moves
compare_routes.py into routes/compare/, leaving a backward-compat
sys.modules shim at the old path. Pure file reorganization, no behavior
change.

The shim uses sys.modules replacement so the `import ... as cr` +
`monkeypatch.setattr(cr, "SessionLocal", ...)` / `"_owned_endpoint_by_url"`
/ `"_owned_endpoint_by_id"` pattern in test_endpoint_owner_scope_followup.py
reaches the canonical module.

Canonical module imports only from core/, src/, and routes.session_routes
(zero dependency on the legacy shim). One source-introspection test site
repointed: test_endpoint_owner_scope_followup.py (shared with other domains;
only the compare entry repointed here).

Adds tests/test_compare_routes_shim.py to pin the sys.modules shim
contract. Verified: compileall clean; targeted tests pass.

app.py

@@ -663,7 +663,7 @@ app.include_router(setup_session_routes(
 ))
 
 # Admin Danger Zone wipes (Settings → System → Danger Zone)
-from routes.admin_wipe_routes import setup_admin_wipe_routes
+from routes.admin_wipe.admin_wipe_routes import setup_admin_wipe_routes
 app.include_router(setup_admin_wipe_routes(session_manager))
 
 # Memory
@@ -704,7 +704,7 @@ from routes.diagnostics_routes import setup_diagnostics_routes
 app.include_router(setup_diagnostics_routes(rag_manager, rag_available, research_handler, memory_vector))
 
 # Cleanup
-from routes.cleanup_routes import setup_cleanup_routes
+from routes.cleanup.cleanup_routes import setup_cleanup_routes
 app.include_router(setup_cleanup_routes(session_manager))
 
 # Personal docs
@@ -787,7 +787,7 @@ from routes.hwfit_routes import setup_hwfit_routes
 app.include_router(setup_hwfit_routes())
 
 # Model A/B Comparison
-from routes.compare_routes import setup_compare_routes
+from routes.compare.compare_routes import setup_compare_routes
 app.include_router(setup_compare_routes(session_manager))
 
 # User Preferences

routes/admin_wipe/__init__.py

@@ -0,0 +1,5 @@
+"""Admin wipe route domain package (slice 2h, #4082/#4071).
+
+Contains admin_wipe_routes.py, migrated from the flat routes/ directory.
+Backward-compat shim at routes/admin_wipe_routes.py re-exports from here.
+"""

routes/admin_wipe/admin_wipe_routes.py

@@ -0,0 +1,176 @@
+"""Admin Danger Zone — per-category wipes.
+
+Each endpoint is admin-only and truncates exactly one domain so the
+user can selectively reset memory / skills / notes / etc. without
+nuking everything. The catch-all `chats` endpoint mirrors the
+existing /api/sessions/all so the Danger Zone speaks one URL pattern.
+
+URL shape: DELETE /api/admin/wipe/{kind}
+Kinds: chats, memory, skills, notes, tasks, documents, gallery, calendar.
+"""
+
+import json
+import logging
+import os
+import shutil
+from fastapi import APIRouter, HTTPException, Request
+
+from core.middleware import require_admin
+from core.database import (
+    SessionLocal,
+    Session as DbSession,
+    ChatMessage as DbChatMessage,
+    Memory,
+    Note,
+    ScheduledTask,
+    TaskRun,
+    Document,
+    DocumentVersion,
+    GalleryImage,
+    GalleryAlbum,
+    CalendarEvent,
+    CalendarCal,
+)
+from src.constants import DATA_DIR, SKILLS_DIR, SKILLS_FILE, GALLERY_DIR, GALLERY_UPLOADS_DIR
+
+logger = logging.getLogger(__name__)
+
+
+def _wipe_memory_files():
+    """Blank memory.json + drop the per-owner tidy-state sidecar so the
+    next audit doesn't try to diff against gone memories."""
+    for name in ("memory.json", "memory_tidy_state.json"):
+        p = os.path.join(DATA_DIR, name)
+        if not os.path.exists(p):
+            continue
+        try:
+            if name == "memory.json":
+                with open(p, "w", encoding="utf-8") as f:
+                    json.dump([], f)
+            else:
+                os.remove(p)
+        except OSError as e:
+            logger.warning(f"Could not reset {name}: {e}")
+
+
+def _rmtree_quiet(path: str):
+    """rmtree that doesn't crash if the path doesn't exist."""
+    if os.path.isdir(path):
+        try:
+            shutil.rmtree(path)
+        except OSError as e:
+            logger.warning(f"Could not remove {path}: {e}")
+
+
+def setup_admin_wipe_routes(session_manager):
+    """The session_manager is passed in so we can also clear its
+    in-memory cache when wiping chats — without it the DB is empty
+    but the next /api/sessions returns stale entries."""
+    router = APIRouter(prefix="/api/admin")
+
+    @router.delete("/wipe/{kind}")
+    def wipe(kind: str, request: Request):
+        require_admin(request)
+        kind = (kind or "").strip().lower()
+
+        db = SessionLocal()
+        try:
+            if kind == "chats":
+                count = db.query(DbSession).count()
+                db.query(DbChatMessage).delete()
+                db.query(DbSession).delete()
+                db.commit()
+                try:
+                    session_manager.sessions.clear()
+                except Exception:
+                    pass
+                return {"status": "deleted", "kind": kind, "count": count}
+
+            if kind == "memory":
+                count = db.query(Memory).count()
+                db.query(Memory).delete()
+                db.commit()
+                _wipe_memory_files()
+                # Drop the vector store too so semantic search doesn't
+                # return ghosts. Lazy import — chromadb may not be
+                # initialised in every deployment.
+                try:
+                    from src.memory_vector import get_memory_vector_store
+                    mv = get_memory_vector_store()
+                    if mv and hasattr(mv, "clear"):
+                        mv.clear()
+                except Exception as e:
+                    logger.info(f"Memory vector clear skipped: {e}")
+                return {"status": "deleted", "kind": kind, "count": count}
+
+            if kind == "skills":
+                # Skills live as SKILL.md files under data/skills/. Drop
+                # the entire directory; the SkillsManager re-creates the
+                # tree on next write.
+                skills_dir = SKILLS_DIR
+                count = 0
+                if os.path.isdir(skills_dir):
+                    # Count SKILL.md files for the response — quick walk.
+                    for _, _, files in os.walk(skills_dir):
+                        count += sum(1 for f in files if f == "SKILL.md")
+                    _rmtree_quiet(skills_dir)
+                # Legacy fallback file
+                legacy = SKILLS_FILE
+                if os.path.exists(legacy):
+                    try:
+                        os.remove(legacy)
+                    except OSError:
+                        pass
+                return {"status": "deleted", "kind": kind, "count": count}
+
+            if kind == "notes":
+                count = db.query(Note).count()
+                db.query(Note).delete()
+                db.commit()
+                return {"status": "deleted", "kind": kind, "count": count}
+
+            if kind == "tasks":
+                # TaskRun rows reference tasks via FK — clear them first.
+                db.query(TaskRun).delete()
+                count = db.query(ScheduledTask).count()
+                db.query(ScheduledTask).delete()
+                db.commit()
+                return {"status": "deleted", "kind": kind, "count": count}
+
+            if kind == "documents":
+                # DocumentVersion FKs Document — clear children first.
+                db.query(DocumentVersion).delete()
+                count = db.query(Document).count()
+                db.query(Document).delete()
+                db.commit()
+                return {"status": "deleted", "kind": kind, "count": count}
+
+            if kind == "gallery":
+                count = db.query(GalleryImage).count() + db.query(GalleryAlbum).count()
+                db.query(GalleryImage).delete()
+                db.query(GalleryAlbum).delete()
+                db.commit()
+                # Also drop the upload dir so disk doesn't keep orphans.
+                _rmtree_quiet(GALLERY_DIR)
+                _rmtree_quiet(GALLERY_UPLOADS_DIR)
+                return {"status": "deleted", "kind": kind, "count": count}
+
+            if kind == "calendar":
+                # Events FK calendars — clear children first, then both.
+                db.query(CalendarEvent).delete()
+                count = db.query(CalendarCal).count()
+                db.query(CalendarCal).delete()
+                db.commit()
+                return {"status": "deleted", "kind": kind, "count": count}
+
+            raise HTTPException(400, f"Unknown wipe kind: {kind!r}")
+        except HTTPException:
+            raise
+        except Exception as e:
+            db.rollback()
+            logger.exception(f"Wipe {kind} failed")
+            raise HTTPException(500, f"Wipe {kind} failed: {e}")
+        finally:
+            db.close()
+
+    return router

routes/admin_wipe_routes.py

@@ -1,176 +1,17 @@
-"""Admin Danger Zone — per-category wipes.
+"""Backward-compat shim — canonical location is routes/admin_wipe/admin_wipe_routes.py.
 
-Each endpoint is admin-only and truncates exactly one domain so the
-user can selectively reset memory / skills / notes / etc. without
-nuking everything. The catch-all `chats` endpoint mirrors the
-existing /api/sessions/all so the Danger Zone speaks one URL pattern.
-
-URL shape: DELETE /api/admin/wipe/{kind}
-Kinds: chats, memory, skills, notes, tasks, documents, gallery, calendar.
+This module is replaced in ``sys.modules`` by the canonical module object so
+that ``import routes.admin_wipe_routes``, ``from routes.admin_wipe_routes
+import X``, ``importlib.import_module("routes.admin_wipe_routes")``, and the
+``import ... as admin_wipe_routes`` + ``monkeypatch.setattr(admin_wipe_routes,
+"SessionLocal", ...)`` / ``"require_admin"`` pattern used by
+test_admin_wipe_gallery.py all operate on the *same* object the application
+actually uses. Keeps existing import paths working after slice 2h
+(#4082/#4071).
 """
 
-import json
-import logging
-import os
-import shutil
-from fastapi import APIRouter, HTTPException, Request
+import sys as _sys
 
-from core.middleware import require_admin
-from core.database import (
-    SessionLocal,
-    Session as DbSession,
-    ChatMessage as DbChatMessage,
-    Memory,
-    Note,
-    ScheduledTask,
-    TaskRun,
-    Document,
-    DocumentVersion,
-    GalleryImage,
-    GalleryAlbum,
-    CalendarEvent,
-    CalendarCal,
-)
-from src.constants import DATA_DIR, SKILLS_DIR, SKILLS_FILE, GALLERY_DIR, GALLERY_UPLOADS_DIR
+from routes.admin_wipe import admin_wipe_routes as _canonical  # noqa: F401
 
-logger = logging.getLogger(__name__)
-
-
-def _wipe_memory_files():
-    """Blank memory.json + drop the per-owner tidy-state sidecar so the
-    next audit doesn't try to diff against gone memories."""
-    for name in ("memory.json", "memory_tidy_state.json"):
-        p = os.path.join(DATA_DIR, name)
-        if not os.path.exists(p):
-            continue
-        try:
-            if name == "memory.json":
-                with open(p, "w", encoding="utf-8") as f:
-                    json.dump([], f)
-            else:
-                os.remove(p)
-        except OSError as e:
-            logger.warning(f"Could not reset {name}: {e}")
-
-
-def _rmtree_quiet(path: str):
-    """rmtree that doesn't crash if the path doesn't exist."""
-    if os.path.isdir(path):
-        try:
-            shutil.rmtree(path)
-        except OSError as e:
-            logger.warning(f"Could not remove {path}: {e}")
-
-
-def setup_admin_wipe_routes(session_manager):
-    """The session_manager is passed in so we can also clear its
-    in-memory cache when wiping chats — without it the DB is empty
-    but the next /api/sessions returns stale entries."""
-    router = APIRouter(prefix="/api/admin")
-
-    @router.delete("/wipe/{kind}")
-    def wipe(kind: str, request: Request):
-        require_admin(request)
-        kind = (kind or "").strip().lower()
-
-        db = SessionLocal()
-        try:
-            if kind == "chats":
-                count = db.query(DbSession).count()
-                db.query(DbChatMessage).delete()
-                db.query(DbSession).delete()
-                db.commit()
-                try:
-                    session_manager.sessions.clear()
-                except Exception:
-                    pass
-                return {"status": "deleted", "kind": kind, "count": count}
-
-            if kind == "memory":
-                count = db.query(Memory).count()
-                db.query(Memory).delete()
-                db.commit()
-                _wipe_memory_files()
-                # Drop the vector store too so semantic search doesn't
-                # return ghosts. Lazy import — chromadb may not be
-                # initialised in every deployment.
-                try:
-                    from src.memory_vector import get_memory_vector_store
-                    mv = get_memory_vector_store()
-                    if mv and hasattr(mv, "clear"):
-                        mv.clear()
-                except Exception as e:
-                    logger.info(f"Memory vector clear skipped: {e}")
-                return {"status": "deleted", "kind": kind, "count": count}
-
-            if kind == "skills":
-                # Skills live as SKILL.md files under data/skills/. Drop
-                # the entire directory; the SkillsManager re-creates the
-                # tree on next write.
-                skills_dir = SKILLS_DIR
-                count = 0
-                if os.path.isdir(skills_dir):
-                    # Count SKILL.md files for the response — quick walk.
-                    for _, _, files in os.walk(skills_dir):
-                        count += sum(1 for f in files if f == "SKILL.md")
-                    _rmtree_quiet(skills_dir)
-                # Legacy fallback file
-                legacy = SKILLS_FILE
-                if os.path.exists(legacy):
-                    try:
-                        os.remove(legacy)
-                    except OSError:
-                        pass
-                return {"status": "deleted", "kind": kind, "count": count}
-
-            if kind == "notes":
-                count = db.query(Note).count()
-                db.query(Note).delete()
-                db.commit()
-                return {"status": "deleted", "kind": kind, "count": count}
-
-            if kind == "tasks":
-                # TaskRun rows reference tasks via FK — clear them first.
-                db.query(TaskRun).delete()
-                count = db.query(ScheduledTask).count()
-                db.query(ScheduledTask).delete()
-                db.commit()
-                return {"status": "deleted", "kind": kind, "count": count}
-
-            if kind == "documents":
-                # DocumentVersion FKs Document — clear children first.
-                db.query(DocumentVersion).delete()
-                count = db.query(Document).count()
-                db.query(Document).delete()
-                db.commit()
-                return {"status": "deleted", "kind": kind, "count": count}
-
-            if kind == "gallery":
-                count = db.query(GalleryImage).count() + db.query(GalleryAlbum).count()
-                db.query(GalleryImage).delete()
-                db.query(GalleryAlbum).delete()
-                db.commit()
-                # Also drop the upload dir so disk doesn't keep orphans.
-                _rmtree_quiet(GALLERY_DIR)
-                _rmtree_quiet(GALLERY_UPLOADS_DIR)
-                return {"status": "deleted", "kind": kind, "count": count}
-
-            if kind == "calendar":
-                # Events FK calendars — clear children first, then both.
-                db.query(CalendarEvent).delete()
-                count = db.query(CalendarCal).count()
-                db.query(CalendarCal).delete()
-                db.commit()
-                return {"status": "deleted", "kind": kind, "count": count}
-
-            raise HTTPException(400, f"Unknown wipe kind: {kind!r}")
-        except HTTPException:
-            raise
-        except Exception as e:
-            db.rollback()
-            logger.exception(f"Wipe {kind} failed")
-            raise HTTPException(500, f"Wipe {kind} failed: {e}")
-        finally:
-            db.close()
-
-    return router
+_sys.modules[__name__] = _canonical

routes/cleanup/__init__.py

@@ -0,0 +1,5 @@
+"""Cleanup route domain package (slice 2g, #4082/#4071).
+
+Contains cleanup_routes.py, migrated from the flat routes/ directory.
+Backward-compat shim at routes/cleanup_routes.py re-exports from here.
+"""

routes/cleanup/cleanup_routes.py

@@ -0,0 +1,60 @@
+# routes/cleanup_routes.py
+"""Routes for cleanup operations."""
+import logging
+from fastapi import APIRouter, HTTPException, Request
+from src.cleanup_service import get_cleanup_preview, cleanup_sessions
+from src.auth_helpers import get_current_user
+
+logger = logging.getLogger(__name__)
+
+def setup_cleanup_routes(session_manager):
+    """
+    Setup cleanup-related routes.
+
+    Args:
+        session_manager: SessionManager instance
+
+    Returns:
+        APIRouter instance with cleanup routes
+    """
+    router = APIRouter(prefix="/api/cleanup")
+
+    @router.get("/preview")
+    async def cleanup_preview(request: Request):
+        """
+        Preview what would be cleaned up without making any changes.
+
+        Returns:
+            JSON response with lists of sessions that would be archived/deleted and estimated space savings
+        """
+        user = get_current_user(request)
+        try:
+            preview = await get_cleanup_preview(owner=user)
+            return preview
+        except Exception as e:
+            logger.error(f"Cleanup preview failed: {e}")
+            raise HTTPException(500, "Cleanup preview generation failed")
+
+    @router.post("")
+    async def cleanup_endpoint(request: Request):
+        """
+        Perform cleanup operations:
+        1. Archive inactive sessions (not accessed for 7 days)
+        2. Delete old sessions (archived, not important, not accessed for 14+ days, with fewer than 10 messages)
+
+        Returns:
+            JSON response with counts of deleted and archived sessions, and space freed
+        """
+        user = get_current_user(request)
+        try:
+            archived_count, deleted_count, space_freed_mb = await cleanup_sessions(session_manager, owner=user)
+            return {
+                "archived_count": archived_count,
+                "deleted_count": deleted_count,
+                "space_freed_mb": round(space_freed_mb, 2)
+            }
+        except Exception as e:
+            logger.error(f"Cleanup failed: {e}")
+            raise HTTPException(500, "Cleanup operation failed")
+
+    return router

routes/cleanup_routes.py

@@ -1,60 +1,17 @@
-# routes/cleanup_routes.py
-"""Routes for cleanup operations."""
-import logging
-from fastapi import APIRouter, HTTPException, Request
-from src.cleanup_service import get_cleanup_preview, cleanup_sessions
-from src.auth_helpers import get_current_user
+"""Backward-compat shim — canonical location is routes/cleanup/cleanup_routes.py.
 
-logger = logging.getLogger(__name__)
+This module is replaced in ``sys.modules`` by the canonical module object so
+that ``import routes.cleanup_routes``, ``from routes.cleanup_routes import X``,
+``importlib.import_module("routes.cleanup_routes")``, and the string-targeted
+``monkeypatch.setattr("routes.cleanup_routes.get_cleanup_preview", ...)`` /
+``"routes.cleanup_routes.get_current_user"`` / ``"routes.cleanup_routes.
+cleanup_sessions"`` pattern used by test_cleanup_owner_scope.py all operate
+on the *same* object the application actually uses. Keeps existing import
+paths working after slice 2g (#4082/#4071).
+"""
 
-def setup_cleanup_routes(session_manager):
-    """
-    Setup cleanup-related routes.
+import sys as _sys
 
-    Args:
-        session_manager: SessionManager instance
+from routes.cleanup import cleanup_routes as _canonical  # noqa: F401
 
-    Returns:
-        APIRouter instance with cleanup routes
-    """
-    router = APIRouter(prefix="/api/cleanup")
-
-    @router.get("/preview")
-    async def cleanup_preview(request: Request):
-        """
-        Preview what would be cleaned up without making any changes.
-
-        Returns:
-            JSON response with lists of sessions that would be archived/deleted and estimated space savings
-        """
-        user = get_current_user(request)
-        try:
-            preview = await get_cleanup_preview(owner=user)
-            return preview
-        except Exception as e:
-            logger.error(f"Cleanup preview failed: {e}")
-            raise HTTPException(500, "Cleanup preview generation failed")
-
-    @router.post("")
-    async def cleanup_endpoint(request: Request):
-        """
-        Perform cleanup operations:
-        1. Archive inactive sessions (not accessed for 7 days)
-        2. Delete old sessions (archived, not important, not accessed for 14+ days, with fewer than 10 messages)
-
-        Returns:
-            JSON response with counts of deleted and archived sessions, and space freed
-        """
-        user = get_current_user(request)
-        try:
-            archived_count, deleted_count, space_freed_mb = await cleanup_sessions(session_manager, owner=user)
-            return {
-                "archived_count": archived_count,
-                "deleted_count": deleted_count,
-                "space_freed_mb": round(space_freed_mb, 2)
-            }
-        except Exception as e:
-            logger.error(f"Cleanup failed: {e}")
-            raise HTTPException(500, "Cleanup operation failed")
-
-    return router
+_sys.modules[__name__] = _canonical

routes/compare/__init__.py

@@ -0,0 +1,5 @@
+"""Compare route domain package (slice 2i, #4082/#4071).
+
+Contains compare_routes.py, migrated from the flat routes/ directory.
+Backward-compat shim at routes/compare_routes.py re-exports from here.
+"""

routes/compare/compare_routes.py

@@ -0,0 +1,365 @@
+# routes/compare_routes.py
+"""Model A/B comparison routes."""
+import json
+import uuid
+import random
+from datetime import datetime
+from fastapi import APIRouter, Form, HTTPException, Request
+from typing import List
+from pydantic import BaseModel
+import logging
+
+from core.database import Comparison, SessionLocal
+from core.session_manager import SessionManager
+from src.auth_helpers import get_current_user
+from routes.session_routes import _reject_raw_endpoint_url_for_non_admin
+
+logger = logging.getLogger(__name__)
+
+router = APIRouter(prefix="/api/compare", tags=["compare"])
+
+
+def _owned_endpoint_by_url(db, base_url, owner):
+    """ModelEndpoint whose base_url == `base_url` and is VISIBLE to `owner`
+    (their own rows + legacy null-owner "shared" rows); None otherwise.
+
+    Owner-scoped on purpose. ModelEndpoint is per-user (core/database.py: non-null
+    owner = private, "the model picker only shows the endpoint to that user") and
+    holds a decrypted `api_key`. start_comparison copies the matched row's api_key
+    into the caller-owned [CMP] session's headers, which then drives that session's
+    /api/chat_stream calls — so an UNSCOPED base_url match would let a user mint a
+    comparison bound to ANOTHER user's private endpoint and spend that owner's
+    api_key / reach whatever base_url they configured. Mirrors
+    session_routes._owned_endpoint. A null/empty owner is a no-op (single-user /
+    legacy mode).
+    """
+    from core.database import ModelEndpoint
+    from src.auth_helpers import owner_filter
+    q = db.query(ModelEndpoint).filter(ModelEndpoint.base_url == base_url)
+    return owner_filter(q, ModelEndpoint, owner).first()
+
+
+def _owned_endpoint_by_id(db, endpoint_id, owner):
+    """ModelEndpoint whose id == `endpoint_id` and is VISIBLE to `owner` (their
+    own rows + legacy null-owner "shared" rows); None otherwise.
+
+    Preferred over _owned_endpoint_by_url for credential resolution: two visible
+    endpoints can share the same base_url but hold DIFFERENT api_keys (e.g. two
+    accounts on the same provider). A base_url-only match returns whichever row
+    sorts first, so it can copy the WRONG owner-scoped key into the [CMP] session.
+    An id pins the exact registered endpoint, so /api/compare/start prefers it and
+    only falls back to URL matching for legacy / admin raw-URL callers. Owner
+    scoping is identical to _owned_endpoint_by_url (a null/empty owner is a no-op).
+    """
+    from core.database import ModelEndpoint
+    from src.auth_helpers import owner_filter
+    q = db.query(ModelEndpoint).filter(ModelEndpoint.id == endpoint_id)
+    return owner_filter(q, ModelEndpoint, owner).first()
+
+
+class RecordVoteRequest(BaseModel):
+    prompt: str
+    models: List[str]
+    winner: str           # model name or "tie"
+    is_blind: bool = True
+
+
+def setup_compare_routes(session_manager: SessionManager):
+    """Setup comparison routes."""
+
+    @router.post("/start")
+    def start_comparison(
+        request: Request,
+        prompt: str = Form(...),
+        model_a: str = Form(...),
+        model_b: str = Form(...),
+        endpoint_a: str = Form(""),
+        endpoint_b: str = Form(""),
+        endpoint_a_id: str = Form(""),
+        endpoint_b_id: str = Form(""),
+        is_blind: str = Form("true"),
+    ):
+        """Create two ephemeral sessions and a comparison record.
+
+        Returns the comparison ID and the two session IDs so the client
+        can fire two independent SSE streams to /api/chat_stream.
+        """
+        user = getattr(request.state, 'current_user', None)
+        comp_id = str(uuid.uuid4())
+        sid_a = str(uuid.uuid4())
+        sid_b = str(uuid.uuid4())
+
+        # Blind mapping: randomly assign left/right
+        blind = str(is_blind).lower() == "true"
+        if blind:
+            mapping = {"left": "a", "right": "b"}
+            if random.random() > 0.5:
+                mapping = {"left": "b", "right": "a"}
+        else:
+            mapping = {"left": "a", "right": "b"}
+
+        # Map session IDs to left/right based on blind mapping
+        session_left = sid_a if mapping["left"] == "a" else sid_b
+        session_right = sid_a if mapping["right"] == "a" else sid_b
+
+        # In blind mode, name the helper sessions by their neutral slot
+        # ("Model A" / "Model B") instead of the real model. Otherwise the
+        # session name leaks the model in the sidebar and GET /api/sessions,
+        # de-anonymizing the comparison before the user votes (issue #1285).
+        slot_name = {session_left: "Model A", session_right: "Model B"}
+
+        # SECURITY: resolve and validate BOTH endpoints before creating any
+        # session. Compare copies a registered endpoint's Authorization header
+        # into the [CMP] session, so validating one endpoint while creating its
+        # session, then rejecting the other, would leave a partial compare
+        # session behind with that header attached. Doing all the owner-scope
+        # resolution + raw-URL rejection up front means a 403 on either endpoint
+        # aborts the whole request with nothing created and no header copied.
+        from src.endpoint_resolver import build_chat_url, build_headers, normalize_base
+        resolved = []
+        db = SessionLocal()
+        try:
+            for sid, model, endpoint, endpoint_id in [
+                (sid_a, model_a, endpoint_a, endpoint_a_id),
+                (sid_b, model_b, endpoint_b, endpoint_b_id),
+            ]:
+                # Prefer an explicit endpoint id: it pins the EXACT registered
+                # endpoint (and its api_key), even when two endpoints visible to
+                # the caller share a base_url with different keys — a URL-only
+                # match would copy whichever row sorts first, i.e. possibly the
+                # wrong key. Fall back to URL resolution only for legacy / admin
+                # raw-URL callers that don't send an id.
+                eid = endpoint_id.strip() if isinstance(endpoint_id, str) else ""
+                if eid:
+                    ep = _owned_endpoint_by_id(db, eid, user)
+                    if ep is None:
+                        # An id the caller can't see (wrong owner / deleted) must
+                        # NOT silently fall back to a same-URL row with a different
+                        # key — that's exactly the mix-up ids exist to prevent.
+                        raise HTTPException(404, "Model endpoint not found")
+                    # The id already resolved the endpoint; ignore any raw URL the
+                    # caller also sent and dial the stored config instead.
+                    endpoint = ep.base_url
+                elif not endpoint:
+                    raise HTTPException(
+                        422, "endpoint_a/endpoint_b or endpoint_a_id/endpoint_b_id is required"
+                    )
+                else:
+                    # Resolve the supplied URL to a ModelEndpoint the caller owns
+                    # (their own rows + legacy null-owner shared rows), scoped so a
+                    # comparison can't borrow another user's private endpoint key.
+                    base = normalize_base(endpoint)
+                    ep = _owned_endpoint_by_url(db, base, user)
+                # Reject *unregistered* raw URLs for signed-in non-admins; a
+                # matched registered endpoint supplies an id so the caller can
+                # still compare endpoints they own. Blanket-rejecting here (the
+                # earlier `endpoint_id=None` call) locked non-admins out of
+                # compare entirely, since compare resolves endpoints by URL with
+                # no endpoint_id. Mirrors the gallery inpaint/harmonize checks.
+                # Raised here (phase 1), before any session exists.
+                _reject_raw_endpoint_url_for_non_admin(
+                    request, user, str(ep.id) if ep is not None else None, endpoint
+                )
+                # Bind the [CMP] session to the RESOLVED endpoint, not the raw
+                # caller-supplied string. When the URL matches a registered
+                # endpoint visible to the caller, use that row's own normalized
+                # base URL (the same value owner scoping + endpoint validation
+                # already vetted) so the session dials exactly where the stored
+                # config points. The raw `endpoint` only survives for callers
+                # allowed to pass one — admins / single-user mode, where
+                # `_reject_raw_endpoint_url_for_non_admin` is a no-op and `ep`
+                # is None. Mirrors the registered-endpoint path in session_routes.
+                session_endpoint_url = (
+                    build_chat_url(normalize_base(ep.base_url)) if ep is not None else endpoint
+                )
+                # Headers come only from a matched endpoint's key; None when
+                # `ep` is None (raw admin URL or no match), so a comparison can
+                # never inherit another user's key/headers.
+                headers = build_headers(ep.api_key, ep.base_url) if (ep and ep.api_key) else None
+                resolved.append((sid, model, session_endpoint_url, headers))
+        finally:
+            db.close()
+
+        # Both endpoints validated — only now create the ephemeral [CMP]
+        # sessions and copy any resolved headers.
+        for sid, model, session_endpoint_url, headers in resolved:
+            name = f"[CMP] {slot_name[sid]}" if blind else f"[CMP] {model.split('/')[-1]}"
+            session_manager.create_session(
+                session_id=sid,
+                name=name,
+                endpoint_url=session_endpoint_url,
+                model=model,
+                rag=False,
+                owner=user,
+            )
+            if headers:
+                s = session_manager.sessions.get(sid)
+                if s:
+                    s.headers = headers
+
+        # Store comparison record
+        db = SessionLocal()
+        try:
+            comp = Comparison(
+                id=comp_id,
+                prompt=prompt,
+                model_a=model_a,
+                model_b=model_b,
+                # Record the URL the session actually dials. For URL callers this
+                # is their raw input; for id-only callers (empty endpoint_a/_b)
+                # fall back to the resolved endpoint URL so the column stays
+                # meaningful and non-null. resolved is in [a, b] order.
+                endpoint_a=endpoint_a or resolved[0][2],
+                endpoint_b=endpoint_b or resolved[1][2],
+                is_blind=blind,
+                blind_mapping=json.dumps(mapping),
+                owner=user,
+            )
+            db.add(comp)
+            db.commit()
+        finally:
+            db.close()
+
+        # In blind mode, withhold the model identities AND the left/right
+        # mapping from the response. The client already knows model_a/model_b
+        # (it sent them), so returning either would defeat blind mode. They are
+        # revealed by POST /api/compare/{id}/vote once the user has voted (#1285).
+        return {
+            "id": comp_id,
+            "session_left": session_left,
+            "session_right": session_right,
+            "model_left": None if blind else (model_a if mapping["left"] == "a" else model_b),
+            "model_right": None if blind else (model_a if mapping["right"] == "a" else model_b),
+            "is_blind": blind,
+            "mapping": None if blind else mapping,
+        }
+
+    @router.post("/{comp_id}/vote")
+    def vote_comparison(
+        request: Request,
+        comp_id: str,
+        winner: str = Form(...),  # "left", "right", or "tie"
+    ):
+        """Record the user's vote and reveal model names if blind."""
+        user = get_current_user(request)
+        db = SessionLocal()
+        try:
+            comp = db.query(Comparison).filter(Comparison.id == comp_id).first()
+            if not comp:
+                raise HTTPException(404, "Comparison not found")
+            # SECURITY: strict ownership — null-owner Comparisons were
+            # accessible to every user.
+            if user and comp.owner != user:
+                raise HTTPException(404, "Comparison not found")
+            if comp.winner:
+                raise HTTPException(400, "Already voted")
+
+            mapping = json.loads(comp.blind_mapping) if comp.blind_mapping else {"left": "a", "right": "b"}
+
+            if winner == "tie":
+                comp.winner = "tie"
+            elif winner == "left":
+                comp.winner = mapping["left"]
+            elif winner == "right":
+                comp.winner = mapping["right"]
+            else:
+                raise HTTPException(400, "winner must be 'left', 'right', or 'tie'")
+
+            comp.voted_at = datetime.utcnow()
+            db.commit()
+
+            return {
+                "winner": comp.winner,
+                "model_a": comp.model_a,
+                "model_b": comp.model_b,
+                "revealed": {
+                    "left": comp.model_a if mapping["left"] == "a" else comp.model_b,
+                    "right": comp.model_a if mapping["right"] == "a" else comp.model_b,
+                },
+            }
+        finally:
+            db.close()
+
+    @router.post("/record")
+    def record_comparison(request: Request, body: RecordVoteRequest):
+        """Lightweight endpoint to record a comparison vote from the frontend."""
+        user = get_current_user(request)
+        comp_id = str(uuid.uuid4())
+
+        model_a = body.models[0] if len(body.models) > 0 else ""
+        model_b = body.models[1] if len(body.models) > 1 else ""
+
+        # For N>2 models, store the full list as JSON in blind_mapping
+        if len(body.models) > 2:
+            blind_mapping = json.dumps({"models": body.models})
+        else:
+            blind_mapping = None
+
+        db = SessionLocal()
+        try:
+            comp = Comparison(
+                id=comp_id,
+                prompt=body.prompt[:500],
+                model_a=model_a,
+                model_b=model_b,
+                endpoint_a="",
+                endpoint_b="",
+                winner=body.winner,
+                is_blind=body.is_blind,
+                blind_mapping=blind_mapping,
+                voted_at=datetime.utcnow(),
+                owner=user,
+            )
+            db.add(comp)
+            db.commit()
+        finally:
+            db.close()
+
+        return {"status": "ok", "id": comp_id}
+
+    @router.get("/history")
+    def list_comparisons(request: Request):
+        """List past comparisons."""
+        user = get_current_user(request)
+        db = SessionLocal()
+        try:
+            q = db.query(Comparison)
+            if user:
+                q = q.filter(Comparison.owner == user)
+            comps = q.order_by(Comparison.created_at.desc()).limit(50).all()
+            return [
+                {
+                    "id": c.id,
+                    "prompt": c.prompt[:100],
+                    "model_a": c.model_a,
+                    "model_b": c.model_b,
+                    "winner": c.winner,
+                    "is_blind": c.is_blind,
+                    "voted_at": c.voted_at.isoformat() if c.voted_at else None,
+                    "created_at": c.created_at.isoformat() if c.created_at else None,
+                }
+                for c in comps
+            ]
+        finally:
+            db.close()
+
+    @router.delete("/{comp_id}")
+    def delete_comparison(request: Request, comp_id: str):
+        """Delete a comparison and its ephemeral sessions."""
+        user = get_current_user(request)
+        db = SessionLocal()
+        try:
+            comp = db.query(Comparison).filter(Comparison.id == comp_id).first()
+            if not comp:
+                raise HTTPException(404, "Comparison not found")
+            # SECURITY: strict ownership — null-owner Comparisons were
+            # accessible to every user.
+            if user and comp.owner != user:
+                raise HTTPException(404, "Comparison not found")
+            db.delete(comp)
+            db.commit()
+            return {"status": "deleted"}
+        finally:
+            db.close()
+
+    return router

routes/compare_routes.py

@@ -1,365 +1,18 @@
-# routes/compare_routes.py
-"""Model A/B comparison routes."""
-import json
-import uuid
-import random
-from datetime import datetime
-from fastapi import APIRouter, Form, HTTPException, Request
-from typing import List
-from pydantic import BaseModel
-import logging
+"""Backward-compat shim — canonical location is routes/compare/compare_routes.py.
 
-from core.database import Comparison, SessionLocal
-from core.session_manager import SessionManager
-from src.auth_helpers import get_current_user
-from routes.session_routes import _reject_raw_endpoint_url_for_non_admin
+This module is replaced in ``sys.modules`` by the canonical module object so
+that ``import routes.compare_routes``, ``from routes.compare_routes import X``,
+``importlib.import_module("routes.compare_routes")``, and the
+``import ... as cr`` + ``monkeypatch.setattr(cr, "SessionLocal", ...)`` /
+``"_owned_endpoint_by_url"`` / ``"_owned_endpoint_by_id"`` pattern used by
+test_endpoint_owner_scope_followup.py all operate on the *same* object the
+application actually uses. Keeps existing import paths working after
+slice 2i (#4082/#4071). Source-introspection tests read the canonical file
+by path.
+"""
 
-logger = logging.getLogger(__name__)
+import sys as _sys
 
-router = APIRouter(prefix="/api/compare", tags=["compare"])
+from routes.compare import compare_routes as _canonical  # noqa: F401
 
-
-def _owned_endpoint_by_url(db, base_url, owner):
-    """ModelEndpoint whose base_url == `base_url` and is VISIBLE to `owner`
-    (their own rows + legacy null-owner "shared" rows); None otherwise.
-
-    Owner-scoped on purpose. ModelEndpoint is per-user (core/database.py: non-null
-    owner = private, "the model picker only shows the endpoint to that user") and
-    holds a decrypted `api_key`. start_comparison copies the matched row's api_key
-    into the caller-owned [CMP] session's headers, which then drives that session's
-    /api/chat_stream calls — so an UNSCOPED base_url match would let a user mint a
-    comparison bound to ANOTHER user's private endpoint and spend that owner's
-    api_key / reach whatever base_url they configured. Mirrors
-    session_routes._owned_endpoint. A null/empty owner is a no-op (single-user /
-    legacy mode).
-    """
-    from core.database import ModelEndpoint
-    from src.auth_helpers import owner_filter
-    q = db.query(ModelEndpoint).filter(ModelEndpoint.base_url == base_url)
-    return owner_filter(q, ModelEndpoint, owner).first()
-
-
-def _owned_endpoint_by_id(db, endpoint_id, owner):
-    """ModelEndpoint whose id == `endpoint_id` and is VISIBLE to `owner` (their
-    own rows + legacy null-owner "shared" rows); None otherwise.
-
-    Preferred over _owned_endpoint_by_url for credential resolution: two visible
-    endpoints can share the same base_url but hold DIFFERENT api_keys (e.g. two
-    accounts on the same provider). A base_url-only match returns whichever row
-    sorts first, so it can copy the WRONG owner-scoped key into the [CMP] session.
-    An id pins the exact registered endpoint, so /api/compare/start prefers it and
-    only falls back to URL matching for legacy / admin raw-URL callers. Owner
-    scoping is identical to _owned_endpoint_by_url (a null/empty owner is a no-op).
-    """
-    from core.database import ModelEndpoint
-    from src.auth_helpers import owner_filter
-    q = db.query(ModelEndpoint).filter(ModelEndpoint.id == endpoint_id)
-    return owner_filter(q, ModelEndpoint, owner).first()
-
-
-class RecordVoteRequest(BaseModel):
-    prompt: str
-    models: List[str]
-    winner: str           # model name or "tie"
-    is_blind: bool = True
-
-
-def setup_compare_routes(session_manager: SessionManager):
-    """Setup comparison routes."""
-
-    @router.post("/start")
-    def start_comparison(
-        request: Request,
-        prompt: str = Form(...),
-        model_a: str = Form(...),
-        model_b: str = Form(...),
-        endpoint_a: str = Form(""),
-        endpoint_b: str = Form(""),
-        endpoint_a_id: str = Form(""),
-        endpoint_b_id: str = Form(""),
-        is_blind: str = Form("true"),
-    ):
-        """Create two ephemeral sessions and a comparison record.
-
-        Returns the comparison ID and the two session IDs so the client
-        can fire two independent SSE streams to /api/chat_stream.
-        """
-        user = getattr(request.state, 'current_user', None)
-        comp_id = str(uuid.uuid4())
-        sid_a = str(uuid.uuid4())
-        sid_b = str(uuid.uuid4())
-
-        # Blind mapping: randomly assign left/right
-        blind = str(is_blind).lower() == "true"
-        if blind:
-            mapping = {"left": "a", "right": "b"}
-            if random.random() > 0.5:
-                mapping = {"left": "b", "right": "a"}
-        else:
-            mapping = {"left": "a", "right": "b"}
-
-        # Map session IDs to left/right based on blind mapping
-        session_left = sid_a if mapping["left"] == "a" else sid_b
-        session_right = sid_a if mapping["right"] == "a" else sid_b
-
-        # In blind mode, name the helper sessions by their neutral slot
-        # ("Model A" / "Model B") instead of the real model. Otherwise the
-        # session name leaks the model in the sidebar and GET /api/sessions,
-        # de-anonymizing the comparison before the user votes (issue #1285).
-        slot_name = {session_left: "Model A", session_right: "Model B"}
-
-        # SECURITY: resolve and validate BOTH endpoints before creating any
-        # session. Compare copies a registered endpoint's Authorization header
-        # into the [CMP] session, so validating one endpoint while creating its
-        # session, then rejecting the other, would leave a partial compare
-        # session behind with that header attached. Doing all the owner-scope
-        # resolution + raw-URL rejection up front means a 403 on either endpoint
-        # aborts the whole request with nothing created and no header copied.
-        from src.endpoint_resolver import build_chat_url, build_headers, normalize_base
-        resolved = []
-        db = SessionLocal()
-        try:
-            for sid, model, endpoint, endpoint_id in [
-                (sid_a, model_a, endpoint_a, endpoint_a_id),
-                (sid_b, model_b, endpoint_b, endpoint_b_id),
-            ]:
-                # Prefer an explicit endpoint id: it pins the EXACT registered
-                # endpoint (and its api_key), even when two endpoints visible to
-                # the caller share a base_url with different keys — a URL-only
-                # match would copy whichever row sorts first, i.e. possibly the
-                # wrong key. Fall back to URL resolution only for legacy / admin
-                # raw-URL callers that don't send an id.
-                eid = endpoint_id.strip() if isinstance(endpoint_id, str) else ""
-                if eid:
-                    ep = _owned_endpoint_by_id(db, eid, user)
-                    if ep is None:
-                        # An id the caller can't see (wrong owner / deleted) must
-                        # NOT silently fall back to a same-URL row with a different
-                        # key — that's exactly the mix-up ids exist to prevent.
-                        raise HTTPException(404, "Model endpoint not found")
-                    # The id already resolved the endpoint; ignore any raw URL the
-                    # caller also sent and dial the stored config instead.
-                    endpoint = ep.base_url
-                elif not endpoint:
-                    raise HTTPException(
-                        422, "endpoint_a/endpoint_b or endpoint_a_id/endpoint_b_id is required"
-                    )
-                else:
-                    # Resolve the supplied URL to a ModelEndpoint the caller owns
-                    # (their own rows + legacy null-owner shared rows), scoped so a
-                    # comparison can't borrow another user's private endpoint key.
-                    base = normalize_base(endpoint)
-                    ep = _owned_endpoint_by_url(db, base, user)
-                # Reject *unregistered* raw URLs for signed-in non-admins; a
-                # matched registered endpoint supplies an id so the caller can
-                # still compare endpoints they own. Blanket-rejecting here (the
-                # earlier `endpoint_id=None` call) locked non-admins out of
-                # compare entirely, since compare resolves endpoints by URL with
-                # no endpoint_id. Mirrors the gallery inpaint/harmonize checks.
-                # Raised here (phase 1), before any session exists.
-                _reject_raw_endpoint_url_for_non_admin(
-                    request, user, str(ep.id) if ep is not None else None, endpoint
-                )
-                # Bind the [CMP] session to the RESOLVED endpoint, not the raw
-                # caller-supplied string. When the URL matches a registered
-                # endpoint visible to the caller, use that row's own normalized
-                # base URL (the same value owner scoping + endpoint validation
-                # already vetted) so the session dials exactly where the stored
-                # config points. The raw `endpoint` only survives for callers
-                # allowed to pass one — admins / single-user mode, where
-                # `_reject_raw_endpoint_url_for_non_admin` is a no-op and `ep`
-                # is None. Mirrors the registered-endpoint path in session_routes.
-                session_endpoint_url = (
-                    build_chat_url(normalize_base(ep.base_url)) if ep is not None else endpoint
-                )
-                # Headers come only from a matched endpoint's key; None when
-                # `ep` is None (raw admin URL or no match), so a comparison can
-                # never inherit another user's key/headers.
-                headers = build_headers(ep.api_key, ep.base_url) if (ep and ep.api_key) else None
-                resolved.append((sid, model, session_endpoint_url, headers))
-        finally:
-            db.close()
-
-        # Both endpoints validated — only now create the ephemeral [CMP]
-        # sessions and copy any resolved headers.
-        for sid, model, session_endpoint_url, headers in resolved:
-            name = f"[CMP] {slot_name[sid]}" if blind else f"[CMP] {model.split('/')[-1]}"
-            session_manager.create_session(
-                session_id=sid,
-                name=name,
-                endpoint_url=session_endpoint_url,
-                model=model,
-                rag=False,
-                owner=user,
-            )
-            if headers:
-                s = session_manager.sessions.get(sid)
-                if s:
-                    s.headers = headers
-
-        # Store comparison record
-        db = SessionLocal()
-        try:
-            comp = Comparison(
-                id=comp_id,
-                prompt=prompt,
-                model_a=model_a,
-                model_b=model_b,
-                # Record the URL the session actually dials. For URL callers this
-                # is their raw input; for id-only callers (empty endpoint_a/_b)
-                # fall back to the resolved endpoint URL so the column stays
-                # meaningful and non-null. resolved is in [a, b] order.
-                endpoint_a=endpoint_a or resolved[0][2],
-                endpoint_b=endpoint_b or resolved[1][2],
-                is_blind=blind,
-                blind_mapping=json.dumps(mapping),
-                owner=user,
-            )
-            db.add(comp)
-            db.commit()
-        finally:
-            db.close()
-
-        # In blind mode, withhold the model identities AND the left/right
-        # mapping from the response. The client already knows model_a/model_b
-        # (it sent them), so returning either would defeat blind mode. They are
-        # revealed by POST /api/compare/{id}/vote once the user has voted (#1285).
-        return {
-            "id": comp_id,
-            "session_left": session_left,
-            "session_right": session_right,
-            "model_left": None if blind else (model_a if mapping["left"] == "a" else model_b),
-            "model_right": None if blind else (model_a if mapping["right"] == "a" else model_b),
-            "is_blind": blind,
-            "mapping": None if blind else mapping,
-        }
-
-    @router.post("/{comp_id}/vote")
-    def vote_comparison(
-        request: Request,
-        comp_id: str,
-        winner: str = Form(...),  # "left", "right", or "tie"
-    ):
-        """Record the user's vote and reveal model names if blind."""
-        user = get_current_user(request)
-        db = SessionLocal()
-        try:
-            comp = db.query(Comparison).filter(Comparison.id == comp_id).first()
-            if not comp:
-                raise HTTPException(404, "Comparison not found")
-            # SECURITY: strict ownership — null-owner Comparisons were
-            # accessible to every user.
-            if user and comp.owner != user:
-                raise HTTPException(404, "Comparison not found")
-            if comp.winner:
-                raise HTTPException(400, "Already voted")
-
-            mapping = json.loads(comp.blind_mapping) if comp.blind_mapping else {"left": "a", "right": "b"}
-
-            if winner == "tie":
-                comp.winner = "tie"
-            elif winner == "left":
-                comp.winner = mapping["left"]
-            elif winner == "right":
-                comp.winner = mapping["right"]
-            else:
-                raise HTTPException(400, "winner must be 'left', 'right', or 'tie'")
-
-            comp.voted_at = datetime.utcnow()
-            db.commit()
-
-            return {
-                "winner": comp.winner,
-                "model_a": comp.model_a,
-                "model_b": comp.model_b,
-                "revealed": {
-                    "left": comp.model_a if mapping["left"] == "a" else comp.model_b,
-                    "right": comp.model_a if mapping["right"] == "a" else comp.model_b,
-                },
-            }
-        finally:
-            db.close()
-
-    @router.post("/record")
-    def record_comparison(request: Request, body: RecordVoteRequest):
-        """Lightweight endpoint to record a comparison vote from the frontend."""
-        user = get_current_user(request)
-        comp_id = str(uuid.uuid4())
-
-        model_a = body.models[0] if len(body.models) > 0 else ""
-        model_b = body.models[1] if len(body.models) > 1 else ""
-
-        # For N>2 models, store the full list as JSON in blind_mapping
-        if len(body.models) > 2:
-            blind_mapping = json.dumps({"models": body.models})
-        else:
-            blind_mapping = None
-
-        db = SessionLocal()
-        try:
-            comp = Comparison(
-                id=comp_id,
-                prompt=body.prompt[:500],
-                model_a=model_a,
-                model_b=model_b,
-                endpoint_a="",
-                endpoint_b="",
-                winner=body.winner,
-                is_blind=body.is_blind,
-                blind_mapping=blind_mapping,
-                voted_at=datetime.utcnow(),
-                owner=user,
-            )
-            db.add(comp)
-            db.commit()
-        finally:
-            db.close()
-
-        return {"status": "ok", "id": comp_id}
-
-    @router.get("/history")
-    def list_comparisons(request: Request):
-        """List past comparisons."""
-        user = get_current_user(request)
-        db = SessionLocal()
-        try:
-            q = db.query(Comparison)
-            if user:
-                q = q.filter(Comparison.owner == user)
-            comps = q.order_by(Comparison.created_at.desc()).limit(50).all()
-            return [
-                {
-                    "id": c.id,
-                    "prompt": c.prompt[:100],
-                    "model_a": c.model_a,
-                    "model_b": c.model_b,
-                    "winner": c.winner,
-                    "is_blind": c.is_blind,
-                    "voted_at": c.voted_at.isoformat() if c.voted_at else None,
-                    "created_at": c.created_at.isoformat() if c.created_at else None,
-                }
-                for c in comps
-            ]
-        finally:
-            db.close()
-
-    @router.delete("/{comp_id}")
-    def delete_comparison(request: Request, comp_id: str):
-        """Delete a comparison and its ephemeral sessions."""
-        user = get_current_user(request)
-        db = SessionLocal()
-        try:
-            comp = db.query(Comparison).filter(Comparison.id == comp_id).first()
-            if not comp:
-                raise HTTPException(404, "Comparison not found")
-            # SECURITY: strict ownership — null-owner Comparisons were
-            # accessible to every user.
-            if user and comp.owner != user:
-                raise HTTPException(404, "Comparison not found")
-            db.delete(comp)
-            db.commit()
-            return {"status": "deleted"}
-        finally:
-            db.close()
-
-    return router
+_sys.modules[__name__] = _canonical

tests/test_admin_wipe_routes_shim.py

@@ -0,0 +1,25 @@
+"""Regression test for the admin_wipe route shim (slice 2h, #4082/#4071).
+
+The backward-compat shim at ``routes/admin_wipe_routes.py`` uses
+``sys.modules`` replacement so the legacy import path and the canonical
+``routes.admin_wipe.*`` path resolve to the *same* module object. This is
+required because ``test_admin_wipe_gallery.py`` does
+``import routes.admin_wipe_routes`` followed by
+``monkeypatch.setattr(routes.admin_wipe_routes, "SessionLocal", ...)`` and
+``"require_admin"`` — for those patches to take effect at runtime, the legacy
+module object and the canonical one must be identical.
+"""
+
+import importlib
+
+import routes.admin_wipe_routes as _shim_admin_wipe  # noqa: F401
+
+
+def test_legacy_and_canonical_admin_wipe_module_are_same_object():
+    """``import routes.admin_wipe_routes`` must alias the canonical module."""
+    legacy = importlib.import_module("routes.admin_wipe_routes")
+    canonical = importlib.import_module("routes.admin_wipe.admin_wipe_routes")
+    assert legacy is canonical, (
+        "routes.admin_wipe_routes shim must resolve to the canonical "
+        "routes.admin_wipe.admin_wipe_routes module object"
+    )

tests/test_cleanup_routes_shim.py

@@ -0,0 +1,25 @@
+"""Regression test for the cleanup route shim (slice 2g, #4082/#4071).
+
+The backward-compat shim at ``routes/cleanup_routes.py`` uses ``sys.modules``
+replacement so the legacy import path and the canonical ``routes.cleanup.*``
+path resolve to the *same* module object. This is required because
+``test_cleanup_owner_scope.py`` uses string-targeted
+``monkeypatch.setattr("routes.cleanup_routes.get_cleanup_preview", ...)`` and
+``monkeypatch.delitem(sys.modules, "routes.cleanup_routes")`` + re-import —
+for those patches to take effect at runtime, the legacy module object and
+the canonical one must be identical.
+"""
+
+import importlib
+
+import routes.cleanup_routes as _shim_cleanup  # noqa: F401
+
+
+def test_legacy_and_canonical_cleanup_module_are_same_object():
+    """``import routes.cleanup_routes`` must alias the canonical module."""
+    legacy = importlib.import_module("routes.cleanup_routes")
+    canonical = importlib.import_module("routes.cleanup.cleanup_routes")
+    assert legacy is canonical, (
+        "routes.cleanup_routes shim must resolve to the canonical "
+        "routes.cleanup.cleanup_routes module object"
+    )

tests/test_compare_routes_shim.py

@@ -0,0 +1,25 @@
+"""Regression test for the compare route shim (slice 2i, #4082/#4071).
+
+The backward-compat shim at ``routes/compare_routes.py`` uses ``sys.modules``
+replacement so the legacy import path and the canonical ``routes.compare.*``
+path resolve to the *same* module object. This is required because
+``test_endpoint_owner_scope_followup.py`` uses ``import routes.compare_routes
+as cr`` followed by ``monkeypatch.setattr(cr, "SessionLocal", ...)`` /
+``"_owned_endpoint_by_url"`` / ``"_owned_endpoint_by_id"`` — for those patches
+to take effect at runtime, the legacy module object and the canonical one
+must be identical.
+"""
+
+import importlib
+
+import routes.compare_routes as _shim_compare  # noqa: F401
+
+
+def test_legacy_and_canonical_compare_module_are_same_object():
+    """``import routes.compare_routes`` must alias the canonical module."""
+    legacy = importlib.import_module("routes.compare_routes")
+    canonical = importlib.import_module("routes.compare.compare_routes")
+    assert legacy is canonical, (
+        "routes.compare_routes shim must resolve to the canonical "
+        "routes.compare.compare_routes module object"
+    )

tests/test_endpoint_owner_scope_followup.py

@@ -358,7 +358,7 @@ def test_compare_start_rejects_unowned_endpoint_id(monkeypatch):
 
 
 def test_compare_endpoint_key_lookup_is_owner_scoped():
-    body = Path("routes/compare_routes.py").read_text(encoding="utf-8")
+    body = Path("routes/compare/compare_routes.py").read_text(encoding="utf-8")
     start_body = body.split("def start_comparison", 1)[1].split("# Store comparison record", 1)[0]
     helper_body = body.split("def _owned_endpoint_by_url", 1)[1].split("class RecordVoteRequest", 1)[0]
     id_helper_body = body.split("def _owned_endpoint_by_id", 1)[1].split("class RecordVoteRequest", 1)[0]