Merge remote-tracking branch 'origin/dev' into fix/editor-followups-20261030

Reconcile branch with current dev (bebf53be).
Resolve conflicts in static/sw.js (bump cache version and preserve panel precache)
and src/ai_interaction.py (preserve upstream quality handling with per-user settings).

Remediate PR #6992 findings:
- A (CI & Playwright): Pin playwright==1.62.0 in requirements-dev and CI workflow; guard browser test imports against pytest runner collection failure.
- B (Per-User Image Model Settings): Support per-user image_model and image_edit_model in editor_image_models() and ai_interaction; enable non-admin preference persistence via /api/prefs fallback.
- C (CodeQL Regex Alert 1212): Replace polynomial-backtracking regex in routes/editor_agent_routes.py with linear token-based intent matcher.
- D (Undo/Redo rembg layer): Clear stale rembgLiveLayer and rembgLiveSnap references in _restoreState() to prevent edge tuner from corrupting detached layers.

static/css/01-agent-chat.css

@@ -4592,7 +4592,9 @@ body.bg-pattern-ascii-fireflies {
       width:100%; background:var(--bg); color:var(--fg);
       border:1px solid var(--border); border-radius:6px;
       padding:8px; font-family:inherit; font-size:0.95rem;
-      resize:vertical; outline:none;
+      resize:both; outline:none;
+      field-sizing:content;
+      max-width:100%; box-sizing:border-box;
       min-height:80px;
     }
     .edit-textarea:focus { border-color:var(--red); }

static/css/17-research.css

@@ -2690,11 +2690,14 @@ body.theme-frosted .modal {
     max-height: 95dvh !important;
   }
 
+  /* Notes and Documents must respect the same viewport and safe-area
+     top as other mobile full-height sheets. Keep these authoritative rules
+     consistent with 05-documents.css and 14-email.css. */
   body.doc-view .doc-editor-pane,
   body.notes-view .notes-pane {
-    inset: auto 0 0 !important;
-    height: 95dvh !important;
-    max-height: 95dvh !important;
+    inset: var(--sheet-top) 0 0 !important;
+    height: calc(var(--app-height) - var(--sheet-top)) !important;
+    max-height: calc(var(--app-height) - var(--sheet-top)) !important;
   }
 }