docs: update skill names from /bd-* to /beads:* (#862)

The Claude Code plugin uses beads:* prefix for slash commands, not bd-*.
Updated all documentation to reflect actual installed command names.

Files updated:
- docs/PLUGIN.md
- docs/INSTALLING.md
- website/docs/integrations/claude-code.md
- website/static/llms-full.txt
- commands/init.md, stats.md, workflow.md

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

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

Executed-By: beads/crew/dave
Rig: beads
Role: crew

website/docs/integrations/claude-code.md

@@ -144,11 +144,11 @@ For enhanced UX with slash commands:
 ```
 
 Adds slash commands:
-- `/bd-ready` - Show ready work
-- `/bd-create` - Create issue
-- `/bd-show` - Show issue
-- `/bd-update` - Update issue
-- `/bd-close` - Close issue
+- `/beads:ready` - Show ready work
+- `/beads:create` - Create issue
+- `/beads:show` - Show issue
+- `/beads:update` - Update issue
+- `/beads:close` - Close issue
 
 ## Troubleshooting