Improve edge-docked window behavior (#2779)

* Make edge-docked windows resizable

Add draggable resize seams for left and right docked windows.

Keep the main chat area from getting too narrow and remember each window's dock width.

* Show emoji shortcodes as icons by default

Keep text-only emoji mode opt-in so model output like 😊 goes through the normal emoji renderer.

* Fix dock resize seams and left dock layout

Hide the resize seam when another floating modal is open, and keep the left-docked window from covering the chat area.

* Keep narrow modal tabs usable

* Fix split layout with both edge docks

* Fix left snap after right dock

* Enable left edge snap for all windows

* Tighten dock resize handle observers

* Use edge docking for settings window

static/app.js

@@ -2497,7 +2497,7 @@ function initializeEventListeners() {
   };
 
   // Keys hidden by default on first run (no localStorage yet)
-  const UI_VIS_DEFAULT_OFF = new Set(['models-section', 'rag-toggle-btn']);
+  const UI_VIS_DEFAULT_OFF = new Set(['models-section', 'rag-toggle-btn', 'text-emojis']);
 
   // Keys that need admin to toggle off (reserved for future use)
   const UI_VIS_ADMIN_ONLY = new Set([]);
@@ -2525,11 +2525,9 @@ function initializeEventListeners() {
     document.querySelectorAll('.section[draggable]').forEach(el => {
       el.setAttribute('draggable', dragEnabled ? 'true' : 'false');
     });
-    // Text-only emojis toggle. Default is ON (the checkbox defaults to
-    // checked because text-emojis isn't in UI_VIS_DEFAULT_OFF), so treat
-    // an absent value as enabled — otherwise the toggle looked on at
-    // startup but the effect only activated after the user flipped it.
-    applyTextEmojis(state['text-emojis'] !== false);
+    // Text-only emojis toggle. Default is OFF so model-emitted shortcodes
+    // like `:blush:` render through the normal monochrome emoji path.
+    applyTextEmojis(state['text-emojis'] === true);
     // Hide thinking sections toggle (show-thinking: checked=show, unchecked=hide)
     document.body.classList.toggle('hide-thinking', state['show-thinking'] === false);
   }