feat: Implement comprehensive help system with contextual icons (#122)

* feat: implement comprehensive help system with contextual icons

- Add HelpModal component with navigation sidebar and 7 help sections
- Add HelpButton component for main header controls
- Add ContextualHelpIcon component for contextual help throughout UI
- Add help icons to all major UI sections:
  - Settings modals (Server Settings, General Settings)
  - Sync button with update system help
  - Tab headers (Available, Downloaded, Installed Scripts)
  - FilterBar and CategorySidebar
- Add comprehensive help content covering:
  - Server Settings: PVE server management, auth types, color coding
  - General Settings: Save filters, GitHub integration, authentication
  - Sync Button: Script metadata syncing explanation
  - Available Scripts: Browsing, filtering, downloading
  - Downloaded Scripts: Local script management and updates
  - Installed Scripts: Auto-detection feature (primary focus), manual management
  - Update System: Automatic/manual update process, release notes
- Improve VersionDisplay: remove 'Update Available' text, add 'Release Notes:' label
- Make help icons more noticeable with increased size
- Fix dark theme compatibility issues in help modal

* fix: resolve linting errors in HelpModal component

- Remove unused Filter import
- Fix unescaped entities by replacing apostrophes and quotes with HTML entities
- All linting errors resolved

* feat: implement release notes modal system

- Add getAllReleases API endpoint to fetch GitHub releases with notes
- Create ReleaseNotesModal component with localStorage version tracking
- Add sticky Footer component with release notes link
- Make version badge clickable to open release notes
- Auto-show modal after updates when version changes
- Track last seen version in localStorage to prevent repeated shows
- Highlight new version in modal when opened after update
- Add manual access via footer and version badge clicks

* fix: use nullish coalescing operator in ReleaseNotesModal

- Replace logical OR (||) with nullish coalescing (??) operator
- Fixes ESLint prefer-nullish-coalescing rule violation
- Ensures build passes successfully

src/app/_components/ResyncButton.tsx

@@ -3,6 +3,7 @@
 import { useState } from 'react';
 import { api } from '~/trpc/react';
 import { Button } from './ui/button';
+import { ContextualHelpIcon } from './ContextualHelpIcon';
 
 export function ResyncButton() {
   const [isResyncing, setIsResyncing] = useState(false);
@@ -44,27 +45,30 @@ export function ResyncButton() {
         Sync scripts with ProxmoxVE repo
       </div>
       <div className="flex flex-col sm:flex-row sm:items-center gap-3">
-        <Button
-          onClick={handleResync}
-          disabled={isResyncing}
-          variant="outline"
-          size="default"
-          className="inline-flex items-center"
-        >
-          {isResyncing ? (
-            <>
-              <div className="animate-spin rounded-full h-5 w-5 border-b-2 border-white mr-2"></div>
-              <span>Syncing...</span>
-            </>
-          ) : (
-            <>
-              <svg className="w-5 h-5 mr-2" fill="none" stroke="currentColor" viewBox="0 0 24 24">
-                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M4 4v5h.582m15.356 2A8.001 8.001 0 004.582 9m0 0H9m11 11v-5h-.581m0 0a8.003 8.003 0 01-15.357-2m15.357 2H15" />
-              </svg>
-              <span>Sync Json Files</span>
-            </>
-          )}
-        </Button>
+        <div className="flex items-center gap-2">
+          <Button
+            onClick={handleResync}
+            disabled={isResyncing}
+            variant="outline"
+            size="default"
+            className="inline-flex items-center"
+          >
+            {isResyncing ? (
+              <>
+                <div className="animate-spin rounded-full h-5 w-5 border-b-2 border-white mr-2"></div>
+                <span>Syncing...</span>
+              </>
+            ) : (
+              <>
+                <svg className="w-5 h-5 mr-2" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                  <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M4 4v5h.582m15.356 2A8.001 8.001 0 004.582 9m0 0H9m11 11v-5h-.581m0 0a8.003 8.003 0 01-15.357-2m15.357 2H15" />
+                </svg>
+                <span>Sync Json Files</span>
+              </>
+            )}
+          </Button>
+          <ContextualHelpIcon section="sync-button" tooltip="Help with Sync Button" />
+        </div>
 
         {lastSync && (
           <div className="text-xs text-muted-foreground">