docs: update daemon CLI syntax from flags to subcommands

Update all documentation to use the new subcommand syntax:
- `bd daemon --start` → `bd daemon start`
- `bd daemon --stop` → `bd daemon stop`
- `bd daemon --status` → `bd daemon status`
- `bd daemon --health` → `bd daemon status --all`
- `--global=false` → `--local`

The old flag syntax is deprecated but still works with warnings.

Closes: bd-734vd

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

claude-plugin/commands/daemon.md

@@ -1,6 +1,6 @@
 ---
 description: Manage background sync daemon
-argument-hint: [start] [stop] [status] [--health]
+argument-hint: [start] [stop] [status]
 ---
 
 Manage the per-project background daemon that handles database connections and syncs with git.
@@ -42,7 +42,7 @@ Each project runs its own daemon at `.beads/bd.sock` for complete database isola
 - **Start**: `bd daemon start` (or auto-starts on first `bd` command)
 - **Stop**: `bd daemon stop`
 - **Status**: `bd daemon status`
-- **Health**: `bd daemon --health` - shows uptime, cache stats, performance metrics
+- **Health**: `bd daemon status --all` - shows uptime, cache stats, performance metrics
 - **Metrics**: `bd daemon --metrics` - detailed operational telemetry
 
 ## Sync Options