feat(plugin): proper Claude Code marketplace registration

- Add .claude-plugin/marketplace.json so the workit repo is a valid
  Claude Code marketplace (automagik-workit)
- install.sh now uses `claude plugin marketplace add` + `claude plugin install`
  with symlink fallback for environments without claude CLI
- Add openclaw.extensions entry + configSchema for OpenClaw registration
- Add minimal index.js entry point for OpenClaw plugin loader

Author: automagik-genie

.claude-plugin/marketplace.json

@@ -1,16 +1,18 @@
 {
-  "$schema": "https://anthropic.com/claude-code/marketplace.schema.json",
-  "name": "workit",
-  "description": "Office work CLI toolkit for agents — Google Workspace + DOCX editing",
-  "owner": { "name": "Automagik" },
+  "name": "automagik-workit",
+  "owner": {
+    "name": "Automagik"
+  },
+  "metadata": {
+    "description": "Plugins by Automagik — Google Workspace tools",
+    "homepage": "https://github.com/automagik-dev/workit"
+  },
   "plugins": [
     {
       "name": "workit",
-      "description": "Agent-native CLI for Google Workspace. 18+ services, local DOCX editing, JSON-first output.",
       "version": "0.12.0",
-      "author": { "name": "Automagik" },
-      "source": ".",
-      "category": "productivity"
+      "source": "./plugins/workit",
+      "description": "Agent-native CLI for Google Workspace. 18+ services, local DOCX editing, JSON-first output, least-privilege auth."
     }
   ]
 }

install.sh

@@ -318,9 +318,23 @@ ok "Plugin installed: ${PLUGIN_DIR}"
 # ---------------------------------------------------------------------------
 # Claude Code integration
 # ---------------------------------------------------------------------------
-mkdir -p "${HOME}/.claude/plugins"
-ln -sfn "$PLUGIN_DIR" "${HOME}/.claude/plugins/workit"
-ok "Claude Code plugin linked: ~/.claude/plugins/workit"
+if command -v claude > /dev/null 2>&1; then
+    # Register workit repo as a marketplace and install the plugin
+    claude plugin marketplace add https://github.com/automagik-dev/workit.git 2>/dev/null || true
+    if claude plugin install workit@automagik-workit 2>/dev/null; then
+        ok "Claude Code plugin installed: workit@automagik-workit"
+    else
+        # Fallback: symlink for older Claude Code versions
+        mkdir -p "${HOME}/.claude/plugins"
+        ln -sfn "$PLUGIN_DIR" "${HOME}/.claude/plugins/workit"
+        ok "Claude Code plugin linked: ~/.claude/plugins/workit (fallback)"
+    fi
+else
+    # Claude Code not installed — symlink for when it is
+    mkdir -p "${HOME}/.claude/plugins"
+    ln -sfn "$PLUGIN_DIR" "${HOME}/.claude/plugins/workit"
+    ok "Claude Code plugin linked: ~/.claude/plugins/workit"
+fi
 
 # ---------------------------------------------------------------------------
 # Codex integration (optional)