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>

examples/monitor-webui/README.md

@@ -231,7 +231,7 @@ Make sure you've initialized a beads database with `bd init` or specify the data
 The monitor requires the daemon to avoid SQLite locking conflicts. Start the daemon first:
 
 ```bash
-bd daemon
+bd daemon start
 ```
 
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