chore: Fix all lint errors and remove unused code

- Fix 75 ESLint errors by updating eslint.config.mjs:
  - Add missing browser globals (MouseEvent, AbortController, Response, etc.)
  - Add Vite define global (__APP_VERSION__)
  - Configure @ts-nocheck to require descriptions
  - Add no-unused-vars rule for .mjs scripts

- Fix runtime bug in agent-output-modal.tsx (setOutput -> setStreamedContent)

- Remove ~120 unused variable warnings across 97 files:
  - Remove unused imports (React hooks, lucide icons, types)
  - Remove unused constants and variables
  - Remove unused function definitions
  - Prefix intentionally unused parameters with underscore

- Add descriptions to all @ts-nocheck comments (25 files)

- Clean up misc issues:
  - Remove invalid deprecation plugin comments
  - Fix eslint-disable comment placement
  - Add missing RefreshCw import in code-view.tsx

Reduces lint warnings from ~300 to 67 (all remaining are no-explicit-any)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/ui/src/components/shared/model-override-trigger.tsx

@@ -1,8 +1,4 @@
-import * as React from 'react';
-import { Settings2 } from 'lucide-react';
 import { cn } from '@/lib/utils';
-import { Button } from '@/components/ui/button';
-import { Popover, PopoverContent, PopoverTrigger } from '@/components/ui/popover';
 import { useAppStore } from '@/store/app-store';
 import type { ModelAlias, CursorModelId, PhaseModelKey, PhaseModelEntry } from '@automaker/types';
 import { PhaseModelSelector } from '@/components/views/settings-view/model-defaults/phase-model-selector';
@@ -74,12 +70,6 @@ export function ModelOverrideTrigger({
     lg: 'h-10 w-10',
   };
 
-  const iconSizes = {
-    sm: 'w-3.5 h-3.5',
-    md: 'w-4 h-4',
-    lg: 'w-5 h-5',
-  };
-
   // For icon variant, wrap PhaseModelSelector and hide text/chevron with CSS
   if (variant === 'icon') {
     return (