feat: add SpecDialog component for editing spec frontmatter

- Implement SpecDialog for managing spec details including title, read mode, priority, and keywords.
- Add validation and keyword management functionality.
- Integrate SpecDialog into SpecsSettingsPage for editing specs.

feat: create index file for specs components

- Export SpecCard, SpecDialog, and related types from a new index file for better organization.

feat: implement SpecsSettingsPage for managing specs and hooks

- Create main settings page with tabs for Project Specs, Personal Specs, Hooks, Injection, and Settings.
- Integrate SpecDialog and HookDialog for editing specs and hooks.
- Add search functionality and mock data for specs and hooks.

feat: add spec management API routes

- Implement API endpoints for listing specs, getting spec details, updating frontmatter, rebuilding indices, and initializing the spec system.
- Handle errors and responses appropriately for each endpoint.

ccw/frontend/src/components/issue/hub/IssueHubTabs.tsx

@@ -8,7 +8,7 @@ import { Button } from '@/components/ui/Button';
 import { cn } from '@/lib/utils';
 
 // Keep in sync with IssueHubHeader/IssueHubPage
-export type IssueTab = 'issues' | 'board' | 'queue' | 'discovery';
+export type IssueTab = 'issues' | 'queue' | 'discovery';
 
 interface IssueHubTabsProps {
   currentTab: IssueTab;
@@ -20,7 +20,6 @@ export function IssueHubTabs({ currentTab, onTabChange }: IssueHubTabsProps) {
 
   const tabs: Array<{ value: IssueTab; label: string }> = [
     { value: 'issues', label: formatMessage({ id: 'issues.hub.tabs.issues' }) },
-    { value: 'board', label: formatMessage({ id: 'issues.hub.tabs.board' }) },
     { value: 'queue', label: formatMessage({ id: 'issues.hub.tabs.queue' }) },
     { value: 'discovery', label: formatMessage({ id: 'issues.hub.tabs.discovery' }) },
   ];