feat: add Claude usage tracking via CLI

Adds a Claude usage tracking feature that displays session, weekly, and Sonnet usage stats. Uses the Claude CLI's /usage command to fetch data (no API key required).

Features:
- Usage popover in board header showing session, weekly, and Sonnet limits
- Progress bars with color-coded status (green/orange/red)
- Auto-refresh with configurable interval
- Caching of usage data with stale indicator
- Settings section for refresh interval configuration

Server:
- ClaudeUsageService: Executes Claude CLI via PTY (expect) to fetch usage
- New /api/claude/usage endpoint

UI:
- ClaudeUsagePopover component with usage cards
- ClaudeUsageSection in settings for configuration
- Integration with app store for persistence

apps/ui/src/components/views/settings-view.tsx

@@ -9,6 +9,7 @@ import { KeyboardMapDialog } from "./settings-view/components/keyboard-map-dialo
 import { DeleteProjectDialog } from "./settings-view/components/delete-project-dialog";
 import { SettingsNavigation } from "./settings-view/components/settings-navigation";
 import { ApiKeysSection } from "./settings-view/api-keys/api-keys-section";
+import { ClaudeUsageSection } from "./settings-view/api-keys/claude-usage-section";
 import { ClaudeCliStatus } from "./settings-view/cli-status/claude-cli-status";
 import { AIEnhancementSection } from "./settings-view/ai-enhancement";
 import { AppearanceSection } from "./settings-view/appearance/appearance-section";
@@ -92,11 +93,14 @@ export function SettingsView() {
     switch (activeView) {
       case "claude":
         return (
-          <ClaudeCliStatus
-            status={claudeCliStatus}
-            isChecking={isCheckingClaudeCli}
-            onRefresh={handleRefreshClaudeCli}
-          />
+          <div className="space-y-6">
+            <ClaudeCliStatus
+              status={claudeCliStatus}
+              isChecking={isCheckingClaudeCli}
+              onRefresh={handleRefreshClaudeCli}
+            />
+            <ClaudeUsageSection />
+          </div>
         );
       case "ai-enhancement":
         return <AIEnhancementSection />;