fix(docs): address Codex review round 1 on the AGENTS.md rewrite

- Restore the universal JSDoc rule the rewrite dropped (module doc
  comment + semantic JSDoc on every export), in root AGENTS.md § Type
  safety and documentation — the generated-catalog RFC cites it as the
  rule the generator enforces at the source.
- Repoint the six remaining citations of moved content that the
  section-name grep missed (rule-title quotes and prose references):
  agent-loop agent.ts, acp index.ts, acp turns.spec.ts, the Exa e2e
  header, the real-api-e2e RFC, the doc-sync-enforcement RFC amendment,
  and rfc/implemented/AGENTS.md's section-name casing.
- Fix two docs/testing.md overstatements: the unit tier also runs
  examples/*/tests specs, and keyless-by-nature examples have no
  with-key smoke.
- Displacement trims keep root AGENTS.md at 1,498/1,500.

packages/ui/acp/tests/turns.spec.ts

@@ -79,7 +79,7 @@ describe('acp bridge — turn outcomes', () => {
   it('the REAL bash tool drives the tool-call UI end-to-end: command title + description block + console output', async () => {
     // Use the SHIPPING tool (dsh-tool-bash + dsh-bash-local), not an inline
     // stand-in, so this verifies the actual presentCall/presentResult the editor
-    // sees (AGENTS.md "prefer the real implementation over a mock in tests").
+    // sees (docs/testing.md "prefer the real implementation over a mock").
     // The mock MODEL still scripts the tool call (no real LLM needed), but the
     // tool and executor are real: a real `echo` runs and its real output flows
     // back through the bridge.