Add cross-project pattern registry for retrieval-augmented generalization

- Create patterns/ directory with README, manifest, and 10 initial patterns
  covering Ollama JSON fallback, API escaping, deprecation, PTY auth,
  queue-poll, LLM-as-parser, credential rotation, reverse proxy binding,
  human approval gates, and transient retry.
- Wire pattern loading into architecture/pipeline.js based on task tags.
- Update architecture/orchestrator.js to load patterns and surface them in
  the system prompt.
- Update MEMORY.md, ARCHITECTURE.md, and CONTEXT.md to document the registry
  and record the decision.

patterns/credential-rotation-recovery.md

@@ -0,0 +1,31 @@
+# Pattern: Credential Rotation and External Service Breakage
+
+## Symptom
+An integration that previously worked starts failing with authentication errors, 401/403 responses, or "invalid token" messages. No code has changed. The root cause is an expired or rotated API key, AppRole secret, OAuth token, or vault credential.
+
+## Affected Projects
+- n8n workflows using AppRole or API keys
+- NocoDB token-based integrations
+- Any service using HashiCorp Vault AppRole authentication
+
+## Root Cause
+Credentials have finite lifetimes or rotation policies. If the integration has no renewal path and the credential is stored in only one place, expiry causes immediate breakage that looks like a code problem.
+
+## Standard Fix
+1. Store credentials in Vault, not in code, config files, or workflow nodes.
+2. Document credential lifetime and rotation procedure in the project RUNBOOK.
+3. Add health checks that verify credential validity without performing risky operations.
+4. Where possible, implement token refresh or AppRole re-login rather than relying on static long-lived tokens.
+5. Alert before expiry, not after.
+
+## When to Apply
+- Every new integration that uses an API key, token, password, or secret.
+- Any existing integration that has no documented credential source or rotation plan.
+
+## Verification
+- Health check passes using the stored credential.
+- Rotation procedure has been tested end-to-end.
+- No secrets are committed to version control.
+
+## Related Patterns
+- `api-version-deprecation`