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/pty-device-code-auth.md

@@ -0,0 +1,29 @@
+# Pattern: PTY-Required Device Code Authentication
+
+## Symptom
+A web app or automation script shells out to a CLI tool (e.g., PowerShell `Connect-MgGraph -UseDeviceAuthentication`) and hangs. The user never sees the device code or authentication URL needed to complete login. The process appears to do nothing.
+
+## Affected Projects
+- Intune Inspector (PowerShell + Microsoft Graph device code auth)
+- Microsoft 365 Admin Toolkit (PowerShell + Microsoft Graph)
+
+## Root Cause
+Some CLI commands write authentication prompts to the console host rather than stdout. When run via `subprocess.Popen` or equivalent without a pseudo-terminal (PTY), that output is not captured or displayed, so the user cannot complete the interactive step.
+
+## Standard Fix
+1. Use a PTY-enabled subprocess library (`pexpect` in Python, `node-pty` in Node.js) so the spawned process believes it has a real terminal.
+2. Capture and surface console-host output to the user in real time (device code, URL, instructions).
+3. Poll for completion if the process is long-running.
+4. Document that this is a workaround for interactive CLI flows that cannot be fully non-interactive.
+
+## When to Apply
+- Any integration that spawns a command-line tool requiring interactive authentication.
+- Microsoft Graph device-code flows, Azure CLI login prompts, OAuth CLI helpers, or similar tools.
+
+## Verification
+- Running the script standalone in a real terminal produces a device code/URL.
+- The app captures and displays the same code/URL via PTY.
+- Authentication completes and the downstream operation succeeds.
+
+## Related Patterns
+- None yet.