chore: prettier format all files, brotli, Sentry release tagging, CI gates

Prettier: auto-formatted 103 files to fix baseline. Prettier check in CI
  is now a hard gate (removed continue-on-error).

Brotli: installed libnginx-mod-http-brotli-filter/static. Enabled in nginx
  with brotli_static on for pre-compressed assets and comp_level 6.

Sentry releases: deploy script now exports VITE_APP_VERSION=<git-short-sha>
  before building so each Sentry release maps to an exact commit.
  CI also passes github.sha as VITE_APP_VERSION.

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

src/app/components/editor/Editor.preview.tsx

@@ -23,7 +23,11 @@ export function EditorPreview() {
 
   return (
     <>
-      <IconButton variant="SurfaceVariant" aria-label="Open editor preview" onClick={() => setOpen(!open)}>
+      <IconButton
+        variant="SurfaceVariant"
+        aria-label="Open editor preview"
+        onClick={() => setOpen(!open)}
+      >
         <Icon src={Icons.BlockQuote} />
       </IconButton>
       <Overlay open={open} backdrop={<OverlayBackdrop />}>
@@ -58,7 +62,12 @@ export function EditorPreview() {
                       >
                         <Icon src={toolbar ? Icons.AlphabetUnderline : Icons.Alphabet} />
                       </IconButton>
-                      <IconButton variant="SurfaceVariant" size="300" radii="300" aria-label="Insert emoji">
+                      <IconButton
+                        variant="SurfaceVariant"
+                        size="300"
+                        radii="300"
+                        aria-label="Insert emoji"
+                      >
                         <Icon src={Icons.Smile} />
                       </IconButton>
                       <IconButton variant="SurfaceVariant" size="300" radii="300" aria-label="Send">