feat: add SQLite database layer with SQLModel

Add shared database infrastructure to clide core for use by both
the CLI and clide-web. SQLModel provides Pydantic-native models
that double as SQLAlchemy table definitions.

Models: Project, Session, UserPreference, ConnectionLog.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

clide/models/__init__.py

@@ -1,6 +1,7 @@
 """Pydantic models for Clide."""
 
 from clide.models.config import ClideSettings, PanelConfig
+from clide.models.db import ConnectionLog, Project, Session, UserPreference
 from clide.models.diff import ChangeType, DiffContent, DiffHunk, DiffLine, DiffViewState
 from clide.models.editor import CursorPosition, EditorState, FileBuffer, Selection
 from clide.models.git import (
@@ -56,4 +57,9 @@ __all__ = [
     "TabInfo",
     "TabType",
     "TAB_ICONS",
+    # Database (SQLModel)
+    "Project",
+    "Session",
+    "UserPreference",
+    "ConnectionLog",
 ]

clide/models/db.py

@@ -0,0 +1,50 @@
+"""SQLModel table models for persistent storage.
+
+These models serve both the standalone Clide TUI and the clide-web server.
+They ARE Pydantic models (SQLModel inherits from BaseModel).
+"""
+
+from datetime import datetime
+
+from sqlmodel import Field, SQLModel
+
+
+class Project(SQLModel, table=True):
+    """A project (git repo) that can be opened in Clide."""
+
+    id: int | None = Field(default=None, primary_key=True)
+    name: str = Field(unique=True, index=True)
+    path: str
+    theme: str = "summer-night"
+    last_accessed: datetime | None = None
+    created_at: datetime = Field(default_factory=datetime.utcnow)
+
+
+class Session(SQLModel, table=True):
+    """A tmux session running a Clide instance (used by clide-web)."""
+
+    id: int | None = Field(default=None, primary_key=True)
+    project_name: str = Field(index=True)
+    tmux_session: str = Field(unique=True)
+    pid: int | None = None
+    status: str = "active"
+    created_at: datetime = Field(default_factory=datetime.utcnow)
+    last_activity: datetime = Field(default_factory=datetime.utcnow)
+
+
+class UserPreference(SQLModel, table=True):
+    """Key-value user preferences persisted across restarts."""
+
+    id: int | None = Field(default=None, primary_key=True)
+    key: str = Field(unique=True, index=True)
+    value: str
+
+
+class ConnectionLog(SQLModel, table=True):
+    """Audit log of browser connections (used by clide-web)."""
+
+    id: int | None = Field(default=None, primary_key=True)
+    project_name: str
+    client_ip: str
+    connected_at: datetime = Field(default_factory=datetime.utcnow)
+    disconnected_at: datetime | None = None

clide/services/database.py

@@ -0,0 +1,48 @@
+"""SQLite database engine and session management.
+
+Used by both standalone Clide and clide-web. The database file
+defaults to ~/.clide/clide.db but is configurable.
+"""
+
+from __future__ import annotations
+
+from collections.abc import Generator
+from pathlib import Path
+
+from sqlmodel import Session as DBSession
+from sqlmodel import SQLModel, create_engine
+
+_engine = None
+
+DEFAULT_DB_PATH = Path.home() / ".clide" / "clide.db"
+
+
+def get_engine(db_path: Path | None = None):
+    """Create or return the SQLAlchemy engine."""
+    global _engine
+    if _engine is None:
+        path = db_path or DEFAULT_DB_PATH
+        path.parent.mkdir(parents=True, exist_ok=True)
+        _engine = create_engine(
+            f"sqlite:///{path}",
+            echo=False,
+            connect_args={"check_same_thread": False},
+        )
+    return _engine
+
+
+def init_db(db_path: Path | None = None) -> None:
+    """Create all tables if they don't exist."""
+    # Import models so SQLModel registers them
+    import clide.models.db  # noqa: F401
+
+    engine = get_engine(db_path)
+    SQLModel.metadata.create_all(engine)
+
+
+def get_db() -> Generator[DBSession, None, None]:
+    """Yield a database session. Usable as a FastAPI dependency or context manager."""
+    if _engine is None:
+        raise RuntimeError("Database not initialized — call init_db() first")
+    with DBSession(_engine) as session:
+        yield session

pyproject.toml

@@ -32,6 +32,8 @@ dependencies = [
     "rich>=13.0.0",
     "watchdog>=4.0.0",
     "wcwidth>=0.2.0",  # Required by vendored pyte
+    "sqlmodel>=0.0.16",
+    "aiosqlite>=0.20",
     # Tree-sitter for syntax highlighting
     "tree-sitter>=0.21.0",
     "tree-sitter-python>=0.21.0",