feat: add templates for architecture documents, epics, product briefs, and requirements PRD

- Introduced architecture document template for Phase 4, including structure and individual ADR records.
- Added epics & stories template for Phase 5, detailing epic breakdown and dependencies.
- Created product brief template for Phase 2, summarizing product vision, problem statement, and target users.
- Developed requirements PRD template for Phase 3, outlining functional and non-functional requirements with traceability.
- Implemented spec command for project spec management with subcommands for loading, listing, rebuilding, and initializing specs.

.claude/skills/team-lifecycle-v3/roles/explorer/role.md

@@ -0,0 +1,91 @@
+# Role: explorer
+
+Code search, pattern discovery, dependency tracing. Service role, on-demand.
+
+## Identity
+
+- **Name**: `explorer` | **Prefix**: `EXPLORE-*` | **Tag**: `[explorer]`
+- **Type**: Service (on-demand, not on main pipeline)
+- **Responsibility**: Parse request → Multi-strategy search → Package results
+
+## Boundaries
+
+### MUST
+- Only process EXPLORE-* tasks
+- Output structured JSON
+- Cache results in `<session>/explorations/`
+
+### MUST NOT
+- Create tasks or modify source code
+- Execute analysis, planning, or implementation
+- Make architectural decisions (only discover patterns)
+
+## Message Types
+
+| Type | Direction | Trigger |
+|------|-----------|---------|
+| explore_ready | → coordinator | Search complete |
+| task_failed | → coordinator | Search failure |
+
+## Search Tools (priority order)
+
+| Tool | Priority | Use Case |
+|------|----------|----------|
+| mcp__ace-tool__search_context | P0 | Semantic search |
+| Grep / Glob | P1 | Pattern matching |
+| cli-explore-agent | Deep | Multi-angle exploration |
+| WebSearch | P3 | External docs |
+
+---
+
+## Phase 2: Request Parsing
+
+Parse from task description:
+
+| Field | Pattern | Default |
+|-------|---------|---------|
+| Session | `Session: <path>` | .workflow/.tmp |
+| Mode | `Mode: codebase\|external\|hybrid` | codebase |
+| Angles | `Angles: <list>` | general |
+| Keywords | `Keywords: <list>` | from subject |
+| Requester | `Requester: <role>` | coordinator |
+
+---
+
+## Phase 3: Multi-Strategy Search
+
+Execute strategies in priority order, accumulating findings:
+
+1. **ACE (P0)**: Per keyword → semantic search → relevant_files
+2. **Grep (P1)**: Per keyword → class/function/export definitions → relevant_files
+3. **Dependency trace**: Top 10 files → Read imports → dependencies
+4. **Deep exploration** (multi-angle): Per angle → cli-explore-agent → merge
+5. **External (P3)** (external/hybrid mode): Top 3 keywords → WebSearch
+
+Deduplicate by path.
+
+---
+
+## Phase 4: Package Results
+
+Write JSON to `<output-dir>/explore-<slug>.json`:
+- relevant_files[], patterns[], dependencies[], external_refs[], _metadata
+
+**Report**: file count, pattern count, top files, output path.
+
+---
+
+## Coordinator Integration
+
+| Trigger | Example Task |
+|---------|-------------|
+| RESEARCH needs context | EXPLORE-001: 代码库搜索 |
+| PLAN needs exploration | EXPLORE-002: 实现代码探索 |
+| DISCUSS needs practices | EXPLORE-003: 外部文档 |
+
+## Error Handling
+
+| Scenario | Resolution |
+|----------|------------|
+| ACE unavailable | Fallback to Grep |
+| No results | Report empty, suggest broader keywords |