ESLint --fix: auto-fix brace-style, indent, semi, no-trailing-spaces

Run eslint --fix across src/ to clear ~1900 mechanical lint errors
surfaced by the @typescript-eslint v8 + react-hooks v7 + react-compiler
upgrade in the React 19 modernization PR.

Issues fixed automatically:
- brace-style (Allman): try/catch one-liners reformatted to multi-line
- indent: tab-vs-space and depth corrections
- semi: missing trailing semicolons
- no-trailing-spaces

No semantic changes. Remaining 701 errors are real-code issues
(set-state-in-effect, rules-of-hooks, no-unsafe-* type checks) that
need manual per-file review.

https://claude.ai/code/session_01GrR87LAqnAEyKG2ZbmQt5Q

src/api/room/widgets/AvatarInfoUser.ts

@@ -20,7 +20,7 @@ export class AvatarInfoUser implements IAvatarInfo
     public prefixFont: string = '';
     public displayOrder: string = 'icon-prefix-name';
     public achievementScore: number = 0;
-	public backgroundId: number = 0;
+    public backgroundId: number = 0;
     public standId: number = 0;
     public overlayId: number = 0;
     public cardBackgroundId: number = 0;