Add date/time context to Librarian agent, emphasize NOT 2024

- librarian.ts: Add 'CRITICAL: DATE AWARENESS' section warning against 2024 searches
- librarian.ts: Update examples to use 2025 instead of 2024
- utils.ts: Add librarian agent to envContext receiver list alongside OmO

🤖 GENERATED WITH ASSISTANCE OF [OhMyOpenCode](https://github.com/code-yeongyu/oh-my-opencode)

src/agents/utils.ts

@@ -75,7 +75,7 @@ export function createBuiltinAgents(
 
     let finalConfig = config
 
-    if (agentName === "OmO" && directory && config.prompt) {
+    if ((agentName === "OmO" || agentName === "librarian") && directory && config.prompt) {
       const envContext = createEnvContext(directory)
       finalConfig = {
         ...config,