feat: add unified usage popover with Claude and Codex tabs

- Created combined UsagePopover component with tab switching between providers
- Added Codex usage API endpoint and service (returns not available message)
- Updated BoardHeader to show single usage button for both providers
- Enhanced type definitions for Codex usage with primary/secondary rate limits
- Wired up Codex usage API in HTTP client

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

apps/server/src/routes/codex/index.ts

@@ -0,0 +1,52 @@
+import { Router, Request, Response } from 'express';
+import { CodexUsageService } from '../../services/codex-usage-service.js';
+import { createLogger } from '@automaker/utils';
+
+const logger = createLogger('Codex');
+
+export function createCodexRoutes(service: CodexUsageService): Router {
+  const router = Router();
+
+  // Get current usage (attempts to fetch from Codex CLI)
+  router.get('/usage', async (req: Request, res: Response) => {
+    try {
+      // Check if Codex CLI is available first
+      const isAvailable = await service.isAvailable();
+      if (!isAvailable) {
+        res.status(503).json({
+          error: 'Codex CLI not found',
+          message: "Please install Codex CLI and run 'codex login' to authenticate",
+        });
+        return;
+      }
+
+      const usage = await service.fetchUsageData();
+      res.json(usage);
+    } catch (error) {
+      const message = error instanceof Error ? error.message : 'Unknown error';
+
+      if (message.includes('not authenticated') || message.includes('login')) {
+        res.status(401).json({
+          error: 'Authentication required',
+          message: "Please run 'codex login' to authenticate",
+        });
+      } else if (message.includes('not available') || message.includes('does not provide')) {
+        // This is the expected case - Codex doesn't provide usage stats
+        res.status(503).json({
+          error: 'Usage statistics not available',
+          message: message,
+        });
+      } else if (message.includes('timed out')) {
+        res.status(504).json({
+          error: 'Command timed out',
+          message: 'The Codex CLI took too long to respond',
+        });
+      } else {
+        logger.error('Error fetching usage:', error);
+        res.status(500).json({ error: message });
+      }
+    }
+  });
+
+  return router;
+}