chore: establish schema-of-schemas workplan and reorganize roadmap

This commit sets up the comprehensive workplan for implementing a
markdown-first schema management system with naming conventions,
versioning, and self-validation capabilities.

## Directory Reorganization

- Renamed `todo/` → `roadmap/` for better organization
- Created `roadmap/schema-of-schemas/` subdirectory
- Moved schema management planning artifacts to dedicated directory

## Planning Artifacts Created

### Workplan & Documentation
- **WORKPLAN.md** (19KB) - Comprehensive 6-phase implementation plan
- **SCHEMA_MANAGEMENT_PROPOSAL.md** - Full analysis with 4 options
- **SCHEMA_MANAGEMENT_SUMMARY.md** - Executive summary
- **README.md** - Quick reference guide

### Example Schema
- **examples/schemas/manpage-schema-v1.md** - Demonstrates markdown format

## Schema Management System Design

### Naming Convention
**Format:** `{domain}-schema-v{major}.{minor}.md`
**Examples:**
- `manpage-schema-v1.0.md`
- `terminology-schema-v1.0.md`
- `api-documentation-schema-v1.0.md`

### Markdown-First Format
Schemas will be markdown files with:
- YAML frontmatter for metadata
- Rich documentation sections
- Embedded JSON schema in code block
- Version history and examples

### Implementation Phases (8-10 days)

**Phase 0:** Planning & Setup ✅ (0.5 days) - COMPLETE
**Phase 1:** Filename Convention (1 day) - NEXT
**Phase 2:** Markdown Loader (2-3 days)
**Phase 3:** Schema-for-Schemas (2 days)
**Phase 4:** Schema Migration (1-2 days)
**Phase 5:** CLI & Documentation (1 day)
**Phase 6:** Testing & Validation (1 day)

### Goals

1. ✅ Establish naming convention
2. ⏳ Implement filename validation
3. ⏳ Create markdown schema loader
4. ⏳ Build schema-for-schemas metaschema
5. ⏳ Migrate 5 existing schemas (remove 2 duplicates)
6. ⏳ Update CLI and documentation

## Updated Tracking

### TODO.md
- Added Schema-of-Schemas as active work item
- Documented Phase 1 tasks and timeline
- Paused capability extraction work

### CHANGELOG.md
- Added schema management system to [Unreleased]
- Documented directory reorganization
- Added "In Progress" section for current work

## Next Steps

Begin Phase 1:
1. Implement schema_naming.py with validation
2. Add unit tests
3. Update CLI schema-ingest command
4. Create naming specification document

## Files Changed

- CHANGELOG.md - Added unreleased schema management features
- TODO.md - Updated active work tracking
- roadmap/ - Reorganized from todo/
- roadmap/schema-of-schemas/ - New planning directory
- examples/schemas/ - Example markdown schema

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

roadmap/schema-of-schemas/README.md

@@ -0,0 +1,94 @@
+# Schema-of-Schemas Implementation
+
+**Project:** Markdown-First Schema System
+**Status:** Planning → Implementation
+**Timeline:** 8-10 days
+
+## Quick Links
+
+- **[WORKPLAN.md](./WORKPLAN.md)** - Detailed implementation plan with phases
+- **[SCHEMA_MANAGEMENT_PROPOSAL.md](./SCHEMA_MANAGEMENT_PROPOSAL.md)** - Full analysis and options
+- **[SCHEMA_MANAGEMENT_SUMMARY.md](./SCHEMA_MANAGEMENT_SUMMARY.md)** - Executive summary
+
+## What We're Building
+
+### Goals
+1. ✅ Filename convention: `{domain}-schema-v{version}.md`
+2. ✅ Markdown-first schema format (documentation + embedded JSON)
+3. ✅ Schema-for-schemas to validate all schemas
+4. ✅ Migrate existing schemas to new format
+5. ✅ Clean up duplicate/legacy schemas
+
+### Why
+- **Consistency:** Enforced naming and versioning
+- **Alignment:** Markdown-first matches MarkiTect philosophy
+- **Documentation:** Rich docs alongside schemas
+- **Validation:** Schema-for-schemas ensures quality
+- **Maintainability:** Clear versions and structure
+
+## Implementation Phases
+
+1. **Phase 0:** Planning & Setup (0.5 days) ← **Current**
+2. **Phase 1:** Filename Convention (1 day)
+3. **Phase 2:** Markdown Loader (2-3 days)
+4. **Phase 3:** Schema-for-Schemas (2 days)
+5. **Phase 4:** Schema Migration (1-2 days)
+6. **Phase 5:** CLI & Docs (1 day)
+7. **Phase 6:** Testing (1 day)
+
+## Current Status
+
+### Completed
+- [x] Directory structure created
+- [x] Planning documents moved to roadmap
+- [x] Comprehensive workplan written
+- [x] Example markdown schema created
+
+### Next Steps
+1. Complete Phase 0 planning artifacts
+2. Begin Phase 1 implementation
+3. Checkpoint review after Phase 1
+
+## Key Decisions
+
+### Naming Convention
+**Format:** `{domain}-schema-v{major}.{minor}.md`
+**Example:** `manpage-schema-v1.0.md`
+
+### Schema Format
+**Markdown with embedded JSON:**
+```markdown
+---
+schema-id: "https://markitect.dev/schemas/manpage/v1"
+version: "1.0.0"
+---
+
+# Manpage Schema v1.0
+
+[Documentation...]
+
+## Schema Definition
+
+```json
+{ ... JSON schema ... }
+```
+```
+
+### Schema Migration Plan
+```
+Old → New
+──────────────────────────────────────────────────
+terminology-schema.json      → terminology-schema-v1.0.md
+api-documentation            → api-documentation-schema-v1.0.md
+enhanced-manpage             → manpage-schema-v2.0.md
+markdown-manpage             → REMOVE (duplicate)
+markdown-manpage-schema.json → REMOVE (duplicate)
+```
+
+## Progress Tracking
+
+Track progress in: `roadmap/schema-of-schemas/IMPLEMENTATION_LOG.md` (to be created)
+
+## Questions?
+
+See the full workplan for detailed implementation steps, risks, and mitigation strategies.