feat(15-02): install OIDC deps, rewrite auth middleware and service

- Install @hono/oidc-auth and jose for OIDC integration
- Rewrite requireAuth middleware with three-way auth: API key, MCP Bearer, OIDC session
- Strip auth.service.ts to API key functions only (remove user/session management)
- Remove all references to getUserCount, getSession, refreshSession from middleware

package.json

@@ -35,6 +35,7 @@
 		"typescript": "^5.9.3"
 	},
 	"dependencies": {
+		"@hono/oidc-auth": "^1.8.1",
 		"@hono/zod-validator": "^0.7.6",
 		"@modelcontextprotocol/sdk": "^1.29.0",
 		"@tailwindcss/vite": "^4.2.1",
@@ -44,6 +45,7 @@
 		"drizzle-orm": "^0.45.1",
 		"framer-motion": "^12.38.0",
 		"hono": "^4.12.8",
+		"jose": "^6.2.2",
 		"lucide-react": "^0.577.0",
 		"react": "^19.2.4",
 		"react-dom": "^19.2.4",