governance: add planning/architecture rule (plan ahead, module map, avoid refactors); propagate to system prompts, AGENTS templates, proposal, and plan

prompts/global/system.llm.md

@@ -21,3 +21,8 @@
 - No deferring tests/docs/refactors needed for clarity/maintainability.
 - TDD by default (tests first). Keep docs current.
 - Use sub-agents/parallelization to maintain quality and speed.
+-
+-- Planning/Architecture --
+- Plan before coding via Questions → Proposal → Plan.
+- Maintain a global architecture/module map; document boundaries.
+- Implement module-by-module; avoid refactors except when assumptions change and plans/docs are updated.

prompts/global/system.md

@@ -75,6 +75,12 @@ You are a coding agent running in the Codex CLI (terminal-based). Be precise, sa
   - Log the change in `docs/devlog/` with context and rationale.
 - Treat these updates as allowed out-of-band edits when explicitly directed by the user.
 
+## Planning and Architecture
+- Plan first, implement second. Use the Questions → Proposal → Plan cycle to reach alignment before coding.
+- Maintain a global architecture and module map; document boundaries and responsibilities up front.
+- Implement module-by-module using the cycle; avoid refactors by designing ahead. Refactors occur only when new information invalidates assumptions and must be reflected in updated proposals/plans and docs.
+- Keep ADRs or an architecture summary under `docs/` current.
+
 ## Zero Technical Debt, Production-Ready Always
 - Safety first, speed second. Never compromise correctness, security, or data safety.
 - No technical debt allowed at any time. Every commit must be production-ready.