add lint/format scripts and fix all biome errors (#233)

Add `lint`, `lint:fix`, `format`, and `format:fix` package.json scripts
backed by biome. Add AGENTS.md rule for agents to run them after changes.
Fix all existing lint and format violations across the codebase.

Co-authored-by: Cursor <cursoragent@cursor.com>

agents/claude.ts

@@ -167,7 +167,10 @@ export const claude = agent({
 
     if (result.exitCode !== 0) {
       const errorMessage =
-        result.stderr || finalOutput || result.stdout || "Unknown error - no output from Claude CLI";
+        result.stderr ||
+        finalOutput ||
+        result.stdout ||
+        "Unknown error - no output from Claude CLI";
       log.error(`Claude CLI exited with code ${result.exitCode}: ${errorMessage}`);
       return {
         success: false,