fix: E308 hooks removal + correct plugin CLI command syntax

E308 FIX:
- Removed "hooks": "./hooks/hooks.json" from plugin.json
- Claude Code v2.0.27+ auto-discovers hooks/hooks.json
- Prevents "Duplicate hooks file detected" error

COMMAND FIX:
- Fixed /plugin add marketplace → /plugin marketplace add
- Now follows official Claude Code CLI syntax

.claude-plugin/plugin.json

@@ -52,8 +52,5 @@
     "./commands/java-new.md",
     "./commands/java-build.md",
     "./commands/java-debug.md"
-  ],
-  "hooks": {
-    "hooks_config_path": "./hooks/hooks.json"
-  }
+  ]
 }

README.md

@@ -64,7 +64,7 @@
 
 ```bash
 # Step 1️⃣ Add the marketplace
-/plugin add marketplace pluginagentmarketplace/custom-plugin-java
+/plugin marketplace add pluginagentmarketplace/custom-plugin-java
 
 # Step 2️⃣ Install the plugin
 /plugin install java-development-assistant@pluginagentmarketplace-java