# M4.2-Infrastructure Implementation Plan

**Milestone:** M4.2-Infrastructure (0.0.4)
**Date:** 2026-02-01
**Orchestrator:** Claude Opus 4.5

## Issue Summary

| Issue | Title                                             | Phase | Priority | Depends On | Est. Tokens | Model  |
| ----- | ------------------------------------------------- | ----- | -------- | ---------- | ----------- | ------ |
| #162  | [EPIC] Mosaic Component Architecture              | -     | -        | All        | 0           | manual |
| #163  | [INFRA-001] Add BullMQ dependencies               | 1     | p0       | none       | 15,000      | haiku  |
| #164  | [INFRA-002] Database schema for job tracking      | 1     | p0       | none       | 40,000      | sonnet |
| #165  | [INFRA-003] BullMQ module setup                   | 1     | p0       | #163       | 45,000      | sonnet |
| #166  | [INFRA-004] Stitcher module structure             | 2     | p0       | #165       | 50,000      | sonnet |
| #167  | [INFRA-005] Runner jobs CRUD and queue submission | 2     | p0       | #164, #165 | 55,000      | sonnet |
| #168  | [INFRA-006] Job steps tracking                    | 2     | p0       | #164, #167 | 45,000      | sonnet |
| #169  | [INFRA-007] Job events and audit logging          | 2     | p0       | #164, #167 | 55,000      | sonnet |
| #170  | [INFRA-008] mosaic-bridge module for Discord      | 3     | p1       | #166       | 55,000      | sonnet |
| #171  | [INFRA-009] Chat command parsing                  | 3     | p1       | #170       | 40,000      | sonnet |
| #172  | [INFRA-010] Herald status updates                 | 3     | p1       | #169, #170 | 50,000      | sonnet |
| #173  | [INFRA-011] WebSocket gateway for job events      | 4     | p1       | #169       | 45,000      | sonnet |
| #174  | [INFRA-012] SSE endpoint for CLI consumers        | 4     | p1       | #169       | 40,000      | sonnet |
| #175  | [INFRA-013] End-to-end test harness               | 5     | p0       | Phase 1-4  | 65,000      | sonnet |
| #176  | [INFRA-014] Integration with M4.1 coordinator     | 5     | p0       | All M4.2   | 75,000      | opus   |
| #179  | fix(security): Update Node.js dependencies        | -     | HIGH     | none       | 12,000      | haiku  |
| #180  | fix(security): Update pnpm in Dockerfiles         | -     | HIGH     | none       | 10,000      | haiku  |
| #181  | fix(security): Update Go stdlib in postgres       | -     | HIGH     | none       | 15,000      | haiku  |

**Total Estimated Tokens:** ~712,000

## Dependency Graph

```
Phase 1: Core Infrastructure (Foundation)
┌───────────────────────────────────────────────────────────────┐
│                                                               │
│   #163 BullMQ deps ──────┬──► #165 BullMQ module             │
│                          │                                    │
│   #164 Database schema ──┼──────────────────────────────────►│
│                          │                                    │
│   #179,#180,#181 ◄───────┴─── Security (parallel anytime)    │
│                                                               │
└───────────────────────────────────────────────────────────────┘
                              │
                              ▼
Phase 2: Stitcher Service
┌───────────────────────────────────────────────────────────────┐
│                                                               │
│   #165 ──► #166 Stitcher module ──────────────────────────►  │
│                                                               │
│   #164,#165 ──► #167 Runner jobs CRUD ──┬──► #168 Job steps  │
│                                         │                     │
│                                         └──► #169 Job events │
│                                                               │
└───────────────────────────────────────────────────────────────┘
                              │
                              ▼
Phase 3: Chat Integration         Phase 4: Real-time Status
┌──────────────────────────┐     ┌────────────────────────────┐
│                          │     │                            │
│ #166 ──► #170 Bridge     │     │ #169 ──► #173 WebSocket    │
│          │               │     │          │                 │
│          ▼               │     │          └──► #174 SSE     │
│     #171 Parser          │     │                            │
│          │               │     │                            │
│          └──┬──► #172    │     │                            │
│  #169 ─────┘   Herald    │     │                            │
│                          │     │                            │
└──────────────────────────┘     └────────────────────────────┘
                              │
                              ▼
Phase 5: Integration
┌───────────────────────────────────────────────────────────────┐
│                                                               │
│   All Phase 1-4 ──► #175 E2E test harness                    │
│                                                               │
│   All M4.2 ──► #176 Integration with M4.1 coordinator        │
│                                                               │
│   All complete ──► #162 EPIC (close)                         │
│                                                               │
└───────────────────────────────────────────────────────────────┘
```

## Execution Plan (2 Parallel Agents Max)

### Wave 0: Security (Can run first, independent)

| Agent A           | Agent B               |
| ----------------- | --------------------- |
| #179 Node.js deps | #180 pnpm Dockerfiles |
| #181 Go stdlib    | -                     |

### Wave 1: Foundation (Phase 1)

| Agent A            | Agent B              |
| ------------------ | -------------------- |
| #163 BullMQ deps   | #164 Database schema |
| #165 BullMQ module | (wait for #163)      |

### Wave 2: Stitcher Core (Phase 2, Part 1)

| Agent A              | Agent B               |
| -------------------- | --------------------- |
| #166 Stitcher module | #167 Runner jobs CRUD |

### Wave 3: Stitcher Events (Phase 2, Part 2)

| Agent A        | Agent B         |
| -------------- | --------------- |
| #168 Job steps | #169 Job events |

### Wave 4: Chat + Real-time (Phase 3 + 4)

| Agent A             | Agent B                |
| ------------------- | ---------------------- |
| #170 Bridge module  | #173 WebSocket gateway |
| #171 Command parser | #174 SSE endpoint      |

### Wave 5: Herald + E2E Setup

| Agent A             | Agent B                       |
| ------------------- | ----------------------------- |
| #172 Herald updates | #175 E2E test harness (start) |

### Wave 6: Integration (Phase 5)

| Agent A           | Agent B               |
| ----------------- | --------------------- |
| #175 E2E complete | #176 M4.1 integration |

### Wave 7: Closure

| Agent A         | Agent B            |
| --------------- | ------------------ |
| Close #162 EPIC | Final verification |

## Quality Gates (Mandatory - Cannot Be Bypassed)

Every issue must pass:

1. **Unit Tests** - TDD required, minimum 85% coverage
2. **Type Check** - `pnpm typecheck` must pass
3. **Lint** - `pnpm lint` must pass
4. **Build** - `pnpm build` must pass
5. **Code Review** - Independent agent review before merge
6. **QA Verification** - Functional testing by separate agent

## Agent Protocol

1. **Before starting:** Read issue details, check dependencies are complete
2. **Create scratchpad:** `docs/scratchpads/{issue#}-{short-name}.md`
3. **Follow TDD:** Write tests first (RED), implement (GREEN), refactor
4. **Commit format:** `<type>(#{issue}): description`
5. **Quality gates:** Run all gates before marking complete
6. **Code review:** Request independent review
7. **Close issue:** Add completion comment with summary

## Orchestrator Checkpoints

- [ ] Wave 0 complete (security)
- [ ] Wave 1 complete (foundation)
- [ ] Wave 2 complete (stitcher core)
- [ ] Wave 3 complete (stitcher events)
- [ ] Wave 4 complete (chat + real-time)
- [ ] Wave 5 complete (herald + E2E setup)
- [ ] Wave 6 complete (integration)
- [ ] Wave 7 complete (closure)
- [ ] All issues closed
- [ ] EPIC #162 closed
- [ ] Token tracking report finalized

## Risk Mitigation

1. **Dependency conflicts:** BullMQ + existing ioredis - Agent must verify compatibility
2. **Schema migrations:** Test on dev database before production
3. **Discord API rate limits:** Implement proper throttling in bridge module
4. **WebSocket scaling:** Design for horizontal scaling from start
5. **Integration complexity:** Phase 5 may require opus-level reasoning

## Notes

- Maximum 2 parallel agents to prevent merge conflicts
- All agents must pull latest before starting work
- Coordinate via git commits, not direct communication
- Security issues are HIGH priority but don't block feature work