feat: unified task.json schema migration and multi-module updates

- Create task-schema.json (JSON Schema draft-07) with 10 field blocks fusing
  Unified JSONL, 6-field Task JSON, and Solution Schema advantages
- Migrate unified-execute-with-file from JSONL to .task/*.json directory scanning
- Migrate 3 producers (lite-plan, plan-converter, collaborative-plan) to
  .task/*.json multi-file output
- Add review-cycle Phase 7.5 export-to-tasks (FIX-*.json) and issue-resolve
  --export-tasks option
- Add schema compatibility annotations to action-planning-agent, workflow-plan,
  and tdd-plan
- Add spec-generator skill phases and templates
- Add memory v2 pipeline (consolidation, extraction, job scheduler, embedder)
- Add secret-redactor utility and core-memory enhancements
- Add codex-lens accuracy benchmarks and staged env config overrides

.claude/skills/spec-generator/templates/product-brief.md

@@ -0,0 +1,133 @@
+# Product Brief Template
+
+Template for generating product brief documents in Phase 2.
+
+## Usage Context
+
+| Phase | Usage |
+|-------|-------|
+| Phase 2 (Product Brief) | Generate product-brief.md from multi-CLI analysis |
+| Output Location | `{workDir}/product-brief.md` |
+
+---
+
+## Template
+
+```markdown
+---
+session_id: {session_id}
+phase: 2
+document_type: product-brief
+status: draft
+generated_at: {timestamp}
+stepsCompleted: []
+version: 1
+dependencies:
+  - spec-config.json
+---
+
+# Product Brief: {product_name}
+
+{executive_summary - 2-3 sentences capturing the essence of the product/feature}
+
+## Vision
+
+{vision_statement - clear, aspirational 1-3 sentence statement of what success looks like}
+
+## Problem Statement
+
+### Current Situation
+{description of the current state and pain points}
+
+### Impact
+{quantified impact of the problem - who is affected, how much, how often}
+
+## Target Users
+
+{for each user persona:}
+
+### {Persona Name}
+- **Role**: {user's role/context}
+- **Needs**: {primary needs related to this product}
+- **Pain Points**: {current frustrations}
+- **Success Criteria**: {what success looks like for this user}
+
+## Goals & Success Metrics
+
+| Goal ID | Goal | Success Metric | Target |
+|---------|------|----------------|--------|
+| G-001 | {goal description} | {measurable metric} | {specific target} |
+| G-002 | {goal description} | {measurable metric} | {specific target} |
+
+## Scope
+
+### In Scope
+- {feature/capability 1}
+- {feature/capability 2}
+- {feature/capability 3}
+
+### Out of Scope
+- {explicitly excluded item 1}
+- {explicitly excluded item 2}
+
+### Assumptions
+- {key assumption 1}
+- {key assumption 2}
+
+## Competitive Landscape
+
+| Aspect | Current State | Proposed Solution | Advantage |
+|--------|--------------|-------------------|-----------|
+| {aspect} | {how it's done now} | {our approach} | {differentiator} |
+
+## Constraints & Dependencies
+
+### Technical Constraints
+- {constraint 1}
+- {constraint 2}
+
+### Business Constraints
+- {constraint 1}
+
+### Dependencies
+- {external dependency 1}
+- {external dependency 2}
+
+## Multi-Perspective Synthesis
+
+### Product Perspective
+{summary of product/market analysis findings}
+
+### Technical Perspective
+{summary of technical feasibility and constraints}
+
+### User Perspective
+{summary of user journey and UX considerations}
+
+### Convergent Themes
+{themes where all perspectives agree}
+
+### Conflicting Views
+{areas where perspectives differ, with notes on resolution approach}
+
+## Open Questions
+
+- [ ] {unresolved question 1}
+- [ ] {unresolved question 2}
+
+## References
+
+- Derived from: [spec-config.json](spec-config.json)
+- Next: [Requirements PRD](requirements.md)
+```
+
+## Variable Descriptions
+
+| Variable | Source | Description |
+|----------|--------|-------------|
+| `{session_id}` | spec-config.json | Session identifier |
+| `{timestamp}` | Runtime | ISO8601 generation timestamp |
+| `{product_name}` | Seed analysis | Product/feature name |
+| `{executive_summary}` | CLI synthesis | 2-3 sentence summary |
+| `{vision_statement}` | CLI product perspective | Aspirational vision |
+| All `{...}` fields | CLI analysis outputs | Filled from multi-perspective analysis |