Restore embedded inline comments in Plan/File/Diff views (#456)

* fix(plan-comments): restore embedded inline comment widgets in Plan view

Reinstate CodeMirror block-widget comments so plan annotations stay anchored to selected lines and preserve drag/selection behavior without floating overlays.

* fix(file-comments): return Files editor comments to embedded widgets

Use inline block widgets for file drafts while keeping full-path draft scoping, so similarly named files no longer risk comment collisions.

* fix(diff-comments): render inline comments through annotation portals

Replace absolute floating positioning with annotation-target portals to keep diff comments attached to their lines across shadow DOM updates.

* chore(comments): remove deprecated floating comment hook

Drop the unused floating-comment implementation now that plan, file, and diff views all use embedded comment rendering paths.

* fix(codemirror): expose gutter width as CSS variable

Measure the current CodeMirror gutter and publish --oc-editor-gutter-width on the editor host so inline widgets can size to the visible code area without hardcoded dimensions.

* fix(context-panel): publish panel width for embedded widgets

Set --oc-context-panel-width on the context panel in both docked and expanded modes so comment widgets can follow the active panel width dynamically.

* fix(file-comments): constrain inline input to editor content width

Use context-panel and editor-gutter CSS variables to cap comment input width to the visible editor content area, keeping action buttons fully visible in no-wrap mode.

* fix(file-comments): constrain inline comment cards to content area

Apply the same variable-based width cap to saved comment cards so card actions stay visible when long lines force horizontal scrolling.

* fix(diff-comments): stabilize new comment annotation identity

Derive new-comment annotation ids from selection side and line range, and reuse that id for portal target lookup and keys to avoid remount glitches.

packages/ui/src/components/layout/ContextPanel.tsx

@@ -194,6 +194,17 @@ export const ContextPanel: React.FC = () => {
     return null;
   }
 
+  const panelStyle: React.CSSProperties = isExpanded
+    ? {
+        ['--oc-context-panel-width' as string]: '100vw',
+      }
+    : {
+        width: `${width}px`,
+        minWidth: `${width}px`,
+        maxWidth: `${width}px`,
+        ['--oc-context-panel-width' as string]: `${width}px`,
+      };
+
   return (
     <aside
       ref={panelRef}
@@ -207,13 +218,7 @@ export const ContextPanel: React.FC = () => {
         isResizing ? 'transition-none' : 'transition-[width] duration-200 ease-in-out'
       )}
       onKeyDownCapture={handlePanelKeyDownCapture}
-      style={isExpanded
-        ? undefined
-        : {
-            width: `${width}px`,
-            minWidth: `${width}px`,
-            maxWidth: `${width}px`,
-          }}
+      style={panelStyle}
     >
       {!isExpanded && (
         <div