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/index.html

@@ -16,13 +16,6 @@
   <link rel="apple-touch-icon" href="/static/icons/icon-192.png">
   <script nonce="{{CSP_NONCE}}">
   window._odysseusLoadTime = Date.now();
-  // Stops iOS focus-zoom on every field; iOS still allows pinch-zoom, other platforms would not.
-  (function(){
-    var ua = navigator.userAgent || '';
-    var isIOS = /iPad|iPhone|iPod/.test(ua) || (/Macintosh/.test(ua) && navigator.maxTouchPoints > 1);
-    var vp = document.querySelector('meta[name="viewport"]');
-    if (isIOS && vp) vp.setAttribute('content', vp.getAttribute('content') + ', maximum-scale=1');
-  })();
   (function(){
     try {
       var t = JSON.parse(localStorage.getItem('odysseus-theme'));