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>

TODO.md

@@ -12,9 +12,37 @@ The structure organizes **future tasks** by their impact, just as a changelog or
 
 This section is for tasks currently being discussed with or worked on by the coding assistant. These are the ephemeral, flow-of-thought tasks.
 
-0. the file TODO.html is legacy i think and can be removed 
+### Schema-of-Schemas Implementation (Active - Phase 1)
 
-### Extract Capability-Capability from Issue-Facade
+**Status:** Phase 1 - Filename Convention & Validation (In Progress)
+**Workplan:** See `roadmap/schema-of-schemas/WORKPLAN.md`
+
+**Current Goals:**
+1. ✅ Establish naming convention: `{domain}-schema-v{major}.{minor}.md`
+2. 🔄 Implement filename validation logic
+3. 🔄 Update CLI with validation
+4. ⏳ Create markdown schema loader
+5. ⏳ Build schema-for-schemas metaschema
+6. ⏳ Migrate existing schemas to new format
+
+**Phase 1 Tasks (Current):**
+- [ ] Write `markitect/schema_naming.py` with validation logic
+- [ ] Add unit tests for filename validation
+- [ ] Update `schema-ingest` command with validation
+- [ ] Create SCHEMA_NAMING_SPEC.md documentation
+
+**Next Phases:**
+- Phase 2: Markdown Schema Loader (2-3 days)
+- Phase 3: Schema-for-Schemas Metaschema (2 days)
+- Phase 4: Schema Migration (1-2 days)
+- Phase 5: CLI & Documentation Updates (1 day)
+- Phase 6: Testing & Validation (1 day)
+
+**Expected Completion:** 8-10 days total
+
+---
+
+### Extract Capability-Capability from Issue-Facade (Paused)
 
 **Context:** Issue-facade currently provides two capabilities:
 1. **issue-tracking** (explicit in CAPABILITY-issue-tracking.yaml) - Issue management across platforms