docs(02-01): complete SQLite database setup plan

Tasks completed: 3/3
- Install Drizzle ORM and SQLite dependencies
- Create database connection factory
- Define task hierarchy schema

SUMMARY: .planning/phases/02-data-layer/02-01-SUMMARY.md

.planning/ROADMAP.md

@@ -64,10 +64,11 @@ Plans:
 **Depends on**: Phase 1
 **Requirements**: TASK-02, TASK-03
 **Research**: Unlikely (Drizzle/SQLite well-documented)
-**Plans**: TBD
+**Plans**: 2 plans
 
 Plans:
-- [ ] 02-01: TBD
+- [x] 02-01: SQLite Database Setup
+- [ ] 02-02: Repository Layer
 
 ### Phase 3: Git Integration
 **Goal**: Git worktree management — create isolated worktrees per agent, preview diffs, integrate changes, cleanup
@@ -135,7 +136,7 @@ Phases execute in numeric order: 1 → 1.1 → 2 → 3 → 4 → 5 → 6 → 7
 |-------|----------------|--------|-----------|
 | 1. Core Infrastructure | 5/5 | Complete | 2026-01-30 |
 | 1.1. Hexagonal Architecture | 6/6 | Complete | 2026-01-30 |
-| 2. Data Layer | 0/? | Not started | - |
+| 2. Data Layer | 1/2 | In progress | - |
 | 3. Git Integration | 0/? | Not started | - |
 | 4. Agent Lifecycle | 0/? | Not started | - |
 | 5. Task Dispatch | 0/? | Not started | - |