refactor: Replace generator with enhanced version

- Extracts full frontmatter metadata (originalDate, notion_*, authors, source)
- Correct date priority: frontmatter → filename → mtime → ctime
- All metadata exposed in index.json for frontend use

Phase 1 quick win complete.

docs/coherence-system.md

@@ -0,0 +1,112 @@
+# The Coherence Loop
+
+## Overview
+
+The Coherence Loop is a recursive self-improvement system for **The Fold Within Earth** website. It continuously monitors, diagnoses, and automatically fixes coherence issues in the site's content and infrastructure.
+
+## How It Works
+
+### 1. Watcher - GitHub Actions Monitoring
+The system uses GitHub Actions to monitor site health on multiple schedules:
+- **Every 4 hours**: Full coherence validation
+- **Daily at midnight**: Comprehensive report generation
+- **On push/PR**: Validation of changes
+
+### 2. Diagnoser - Automated Issue Identification
+The diagnostic layer checks:
+- **Frontmatter completeness**: Validates required fields in all fieldnotes
+- **Metadata integrity**: Ensures metadata.yaml files are valid and complete
+- **Link coherence**: Detects broken internal and external links
+- **File structure**: Verifies content follows expected patterns
+
+### 3. Fixer - Auto-Patching Common Issues
+When issues are tagged with `needs-auto-fix`, the system can:
+- Add missing frontmatter templates
+- Fix metadata formatting issues
+- Regenerate index files
+- Create pull requests with fixes
+
+### 4. Witness - Human Review Validation
+Human reviewers validate improvements through:
+- Pull request reviews
+- Issue triage
+- Project board management
+- Discussion participation
+
+## Cycles
+
+### Automated Cycle (Every 4 Hours)
+```mermaid
+graph TD
+    A[Watcher: Check triggers] --> B[Diagnoser: Run validation]
+    B --> C{Issues found?}
+    C -->|Yes| D[Fixer: Create auto-fix PR]
+    C -->|No| E[Report: Log success]
+    D --> F[Witness: Human review]
+    F --> G[Merge if approved]
+    E --> A
+```
+
+### Daily Cycle (Midnight)
+1. Generate comprehensive coherence report
+2. Post to GitHub Discussions
+3. Update project board with new issues
+4. Archive completed items
+
+### Weekly Cycle (Full Review)
+1. Review all open PRs
+2. Audit project board columns
+3. Update documentation
+4. Refine automation rules
+
+## Roles
+
+| Role | Actor | Responsibilities |
+|------|-------|-------------------|
+| **Developer** | GitHub Actions | Automated checks, fixes, reporting |
+| **Tester** | Automated scripts | Validation, link checking, schema verification |
+| **User** | Community members | Issue reporting, feedback |
+| **Witness** | Human reviewers | PR review, triage, quality assurance |
+
+## Metrics
+
+The system tracks:
+- **Coherence Score**: Overall site health (0-100)
+- **Issue Density**: Issues per content file
+- **Fix Rate**: Automated vs manual fixes
+- **Response Time**: Time from issue to resolution
+
+## Configuration
+
+### Workflow Files
+- `.github/workflows/coherence-check.yml` - Primary validation
+- `.github/workflows/auto-fix.yml` - Automated fixes
+- `.github/workflows/daily-report.yml` - Daily reporting
+
+### Scripts
+- `tools/coherence-check.py` - Main validation script
+- `tools/generate-index.mjs` - Index generation with validation
+
+### Templates
+- `docs/fieldnote-template.md` - Frontmatter template
+- `docs/coherence-system.md` - This documentation
+
+## Getting Started
+
+### Reporting Issues
+1. Use the "Coherence Issue" template
+2. Select the appropriate error type and severity
+3. Provide clear reproduction steps
+
+### Contributing Fixes
+1. Fork the repository
+2. Create a feature branch
+3. Make your changes
+4. Run `python tools/coherence-check.py` locally
+5. Submit a PR
+
+## Support
+
+- **Documentation**: See `docs/` folder
+- **Discussions**: Use GitHub Discussions
+- **Issues**: Open a GitHub issue