Add command documentation and improve daemon UX

- Added human-readable uptime formatting (51m 59s vs 3119.4 seconds)
- Fixed daemon stop race condition with SIGKILL
- Added markdown docs for 19 commands: blocked, comments, compact, daemon,
  delete, dep, epic, export, import, label, list, quickstart, rename-prefix,
  renumber, reopen, repos, restore, stale, sync
- Closed: bd-159, bd-152, bd-168
- Deleted test issues: bd-144, bd-145

Amp-Thread-ID: https://ampcode.com/threads/T-9f7c3fed-62de-4bcd-a059-8c1b77cdb841
Co-authored-by: Amp <amp@ampcode.com>

commands/daemon.md

@@ -0,0 +1,35 @@
+---
+description: Run background sync daemon
+argument-hint: [--global] [--stop] [--status] [--health]
+---
+
+Run a background daemon that manages database connections and optionally syncs with git.
+
+## Daemon Modes
+
+- **Local daemon**: Socket at `.beads/bd.sock` (per-repository)
+- **Global daemon**: Socket at `~/.beads/bd.sock` (all repositories)
+
+## Common Operations
+
+- **Start**: `bd daemon` or `bd daemon --global`
+- **Stop**: `bd daemon --stop` or `bd daemon --global --stop`
+- **Status**: `bd daemon --status` or `bd daemon --global --status`
+- **Health**: `bd daemon --health` - shows uptime, cache stats, performance metrics
+- **Metrics**: `bd daemon --metrics` - detailed operational telemetry
+
+## Sync Options
+
+- **--auto-commit**: Automatically commit JSONL changes
+- **--auto-push**: Automatically push commits to remote
+- **--interval**: Sync check interval (default: 5m)
+
+## Migration
+
+- **--migrate-to-global**: Migrate from local to global daemon
+
+The daemon provides:
+- Connection pooling and caching
+- Better performance for frequent operations
+- Automatic JSONL sync
+- Optional git sync