Fix Navidrome automatic library scan schedule (#101)

## Summary
- Fix env var name from `ND_SCANSCHEDULE` to `ND_SCANNER_SCHEDULE` (Navidrome uses viper config where dots become underscores)
- Use explicit `@every 1h` format for clarity
- Reorder CLAUDE.md rules to emphasize running zk-docs first

## Root Cause
Navidrome logs showed "Periodic scan is DISABLED" at startup despite the env var being set. The config key is `scanner.schedule`, which translates to `ND_SCANNER_SCHEDULE` (not `ND_SCANSCHEDULE`).

## Deployment and Testing
- [ ] Sync navidrome app: `argocd app sync navidrome`
- [ ] Verify pod restarts with new env var
- [ ] Check logs for "Scheduling scanner" message instead of "Periodic scan is DISABLED"
- [ ] Wait ~1 hour and confirm scan runs automatically

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

Reviewed-on: https://forge.ops.eblu.me/eblume/blumeops/pulls/101

docs/changelog.d/fix-navidrome-scan-schedule.bugfix.md

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+Fix Navidrome automatic library scan by correcting env var name from `ND_SCANSCHEDULE` to `ND_SCANNER_SCHEDULE`