chore(agents): add CEO daily notes and rewrite founding-engineer/plan-reviewer configs

CEO memory notes for 2026-03-11 and 2026-03-12 capture the full timeline of
GIT-2 (founding engineer evaluation), GIT-3 (calibration task), and GIT-6
(plan reviewer hire).

Founding Engineer: AGENTS.md rewritten from 25-line boilerplate to 3-layer
progressive disclosure model (AGENTS.md core -> DOMAIN.md reference ->
SOUL.md persona). Adds HEARTBEAT.md checklist, TOOLS.md placeholder. Key
changes: memory system reference, async runtime warning, schema gotchas,
UTF-8 boundary safety, search import privacy.

Plan Reviewer: new agent created with AGENTS.md (review workflow, severity
levels, codebase context), HEARTBEAT.md, SOUL.md. Reviews implementation
plans in Paperclip issues before code is written.

agents/plan-reviewer/HEARTBEAT.md

@@ -0,0 +1,37 @@
+# HEARTBEAT.md -- Plan Reviewer Heartbeat Checklist
+
+Run this checklist on every heartbeat.
+
+## 1. Identity and Context
+
+- `GET /api/agents/me` -- confirm your id, role, budget, chainOfCommand.
+- Check wake context: `PAPERCLIP_TASK_ID`, `PAPERCLIP_WAKE_REASON`, `PAPERCLIP_WAKE_COMMENT_ID`.
+
+## 2. Get Assignments
+
+- `GET /api/companies/{companyId}/issues?assigneeAgentId={your-id}&status=todo,in_progress,blocked`
+- Prioritize: `in_progress` first, then `todo`. Skip `blocked` unless you can unblock it.
+- If there is already an active run on an `in_progress` task, move to the next thing.
+- If `PAPERCLIP_TASK_ID` is set and assigned to you, prioritize that task.
+
+## 3. Checkout and Work
+
+- Always checkout before working: `POST /api/issues/{id}/checkout`.
+- Never retry a 409 -- that task belongs to someone else.
+- Do the review. Update status and comment when done.
+
+## 4. Review Workflow
+
+For every plan review task:
+
+1. **Read the issue** -- understand the full description and `<plan>` block.
+2. **Read comments** -- understand discussion context and engineer intent.
+3. **Read parent issue** -- understand the broader goal.
+4. **Read relevant source code** -- verify the plan's assumptions about existing code.
+5. **Write your review** -- append `<review>` block to the issue description.
+6. **Comment** -- leave a summary comment and reassign to the engineer.
+
+## 5. Exit
+
+- Comment on any in_progress work before exiting.
+- If no assignments and no valid mention-handoff, exit cleanly.