feat: monorepo consolidation — forge pipeline, MACP protocol, framework plugin, profiles/guides/skills

Work packages completed:
- WP1: packages/forge — pipeline runner, stage adapter, board tasks, brief classifier,
  persona loader with project-level overrides. 89 tests, 95.62% coverage.
- WP2: packages/macp — credential resolver, gate runner, event emitter, protocol types.
  65 tests, 96.24% coverage. Full Python-to-TS port preserving all behavior.
- WP3: plugins/mosaic-framework — OC rails injection plugin (before_agent_start +
  subagent_spawning hooks for Mosaic contract enforcement).
- WP4: profiles/ (domains, tech-stacks, workflows), guides/ (17 docs),
  skills/ (5 universal skills), forge pipeline assets (48 markdown files).

Board deliberation: docs/reviews/consolidation-board-memo.md
Brief: briefs/monorepo-consolidation.md

Consolidates mosaic/stack (forge, MACP, bootstrap framework) into mosaic/mosaic-stack.
154 new tests total. Zero Python — all TypeScript/ESM.

packages/forge/pipeline/rails/worker-rails.md

@@ -0,0 +1,40 @@
+# Worker Rails
+
+## Constraints for Coding Stage Workers
+
+### MUST
+
+- Work only on files listed in the context packet
+- Follow patterns specified in the implementation spec
+- Use git worktree at `~/src/<repo>-worktrees/<task-slug>`
+- Push to a feature branch
+- Open a PR with description referencing the task ID
+- Run lint + typecheck + unit tests before declaring done
+- Self-check against acceptance criteria
+
+### MUST NOT
+
+- Make architectural decisions (those were made in Planning 1-2)
+- Refactor unrelated code
+- Edit files outside write scope
+- Introduce new dependencies without spec approval
+- Change API contracts without spec approval
+- Merge PRs (workers NEVER merge)
+- Skip tests defined in acceptance criteria
+- Work in main checkout or /tmp (always worktree)
+
+### On Confusion
+
+If the context packet is unclear or the spec seems wrong:
+
+1. Do NOT guess and proceed
+2. Do NOT make your own architectural decisions
+3. STOP and report the ambiguity back to the orchestrator
+4. The orchestrator will route the question back to the appropriate planning stage
+
+### On Completion
+
+1. Push branch
+2. Open PR
+3. Report: task ID, branch name, acceptance criteria status
+4. EXIT — do not continue to other tasks