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/views/board-view/hooks/use-board-actions.ts

@@ -1,4 +1,4 @@
-// @ts-nocheck
+// @ts-nocheck - feature update logic with partial updates and image/file handling
 import { useCallback } from 'react';
 import {
   Feature,

apps/ui/src/components/views/board-view/hooks/use-board-column-features.ts

@@ -1,4 +1,4 @@
-// @ts-nocheck
+// @ts-nocheck - column filtering logic with dependency resolution and status mapping
 import { useMemo, useCallback } from 'react';
 import { Feature, useAppStore } from '@/store/app-store';
 import {
@@ -51,7 +51,6 @@ export function useBoardColumnFeatures({
 
     // Determine the effective worktree path and branch for filtering
     // If currentWorktreePath is null, we're on the main worktree
-    const effectiveWorktreePath = currentWorktreePath || projectPath;
     // Use the branch name from the selected worktree
     // If we're selecting main (currentWorktreePath is null), currentWorktreeBranch
     // should contain the main branch's actual name, defaulting to "main"

apps/ui/src/components/views/board-view/hooks/use-board-drag-drop.ts

@@ -23,7 +23,7 @@ interface UseBoardDragDropProps {
 
 export function useBoardDragDrop({
   features,
-  currentProject,
+  currentProject: _currentProject,
   runningAutoTasks,
   persistFeatureUpdate,
   handleStartImplementation,