refactor(plugin): restructure claude-plugin with proper .claude-plugin directory

Restructure the Claude Code plugin to follow the official plugin manifest
structure with plugin.json in .claude-plugin/ subdirectory and hooks.json
in hooks/ subdirectory.

Changes:
- Add .claude-plugin/plugin.json manifest with name, version, and hooks path
- Move hooks.json to hooks/hooks.json subdirectory
- Update README installation instructions for correct plugin directory path

Author: MasuRii

packages/claude-plugin/.claude-plugin/plugin.json

@@ -0,0 +1,6 @@
+{
+  "name": "recursor-bridge",
+  "version": "0.1.0",
+  "description": "Forwards Claude Code hook events to the ReCursor bridge CLI.",
+  "hooks": "./hooks/hooks.json"
+}

packages/claude-plugin/README.md

@@ -4,11 +4,14 @@ Forwards Claude Code events to the ReCursor bridge server for mobile consumption
 
 ## Installation
 
-Copy this plugin to your Claude Code plugins directory:
+Copy this plugin into the standard Claude plugin directory structure:
 
 ```bash
-mkdir -p ~/.claude-code/plugins/recursor-bridge
-cp hooks.json ~/.claude-code/plugins/recursor-bridge/hooks.json
+mkdir -p ~/.claude/plugins/recursor-bridge/.claude-plugin
+mkdir -p ~/.claude/plugins/recursor-bridge/hooks
+cp .claude-plugin/plugin.json ~/.claude/plugins/recursor-bridge/.claude-plugin/plugin.json
+cp hooks/hooks.json ~/.claude/plugins/recursor-bridge/hooks/hooks.json
+cp README.md ~/.claude/plugins/recursor-bridge/README.md
 ```
 
 ## Configuration