chore(harness): make repository agent-ready

Add concise routed context, task-aware agent roles, focused skills, and structured learning promotion.\n\nUnify local development and workspace tooling, add layered test and E2E verification, harden MCP authentication, and gate deployment behind verification and explicit production promotion.

.agents/ralph/PROMPT_build.md

@@ -40,7 +40,8 @@ If the story details are empty or missing, STOP and report that the PRD story fo
 - Implement completely; no placeholders or stubs.
 - If No-commit is true, do NOT commit or push changes.
 - Do NOT edit the PRD JSON (status is handled by the loop).
-- All changes made during the run must be committed (including updates to progress/logs).
+- Commit only task-owned source, tests, and maintained documentation. Runtime logs
+  and evidence remain ignored.
  - Before committing, perform a final **security**, **performance**, and **regression** review of your changes.
 
 ## Your Task (Do this in order)
@@ -60,7 +61,7 @@ If the story details are empty or missing, STOP and report that the PRD story fo
    - **Performance:** check for avoidable regressions (extra queries, heavy loops, unnecessary re-renders).
    - **Regression:** verify existing behavior that could be impacted still works.
 10. If No-commit is false, commit changes using the `$commit` skill.
-    - Stage everything: `git add -A`
+    - Stage only the files owned by this story; never blanket-stage unrelated work.
     - Confirm a clean working tree after commit: `git status --porcelain` should be empty.
     - After committing, capture the commit hash and subject using:
       `git show -s --format="%h %s" HEAD`.
@@ -103,7 +104,9 @@ Otherwise, end normally without the signal.
 - When authoring documentation, capture the why (tests + implementation intent).
 - If you learn how to run/build/test the project, update {{AGENTS_PATH}} briefly (operational only).
 - Keep AGENTS operational only; progress notes belong in {{PROGRESS_PATH}}.
-- If you hit repeated errors, log them in {{ERRORS_LOG_PATH}} and add a Sign to {{GUARDRAILS_PATH}} using {{GUARDRAILS_REF}} as the template.
+- If you reproduce a reusable failure, record it using
+  `.agents/learnings/TEMPLATE.md`. Promote it only after review into a maintained
+  doc, skill, fixture, or executable invariant; do not add speculative Signs.
 
 ## Activity Logging (Required)
 Log major actions to {{ACTIVITY_LOG_PATH}} using the helper: