feat: add plugin architecture

extensions/voice-call/README.md

@@ -0,0 +1,64 @@
+# Voice Call Plugin (Placeholder)
+
+This is a **stub** plugin used to validate the Clawdbot plugin API.
+It does not place real calls yet.
+
+## Install (local dev)
+
+Option 1: copy into your global extensions folder:
+
+```bash
+mkdir -p ~/.clawdbot/extensions
+cp -R extensions/voice-call ~/.clawdbot/extensions/voice-call
+cd ~/.clawdbot/extensions/voice-call && pnpm install
+```
+
+Option 2: add via config:
+
+```json5
+{
+  plugins: {
+    load: { paths: ["/absolute/path/to/extensions/voice-call"] },
+    entries: {
+      "voice-call": { enabled: true, config: { provider: "twilio" } }
+    }
+  }
+}
+```
+
+Restart the Gateway after changes.
+
+## CLI
+
+```bash
+clawdbot voicecall status
+clawdbot voicecall start --to "+15555550123" --message "Hello"
+```
+
+## Tool
+
+Tool name: `voice_call`
+
+Parameters:
+- `mode`: `"call" | "status"`
+- `to`: target string
+- `message`: optional intro text
+
+## Gateway RPC
+
+- `voicecall.status`
+
+## Skill
+
+The repo includes `skills/voice-call/SKILL.md` for agent guidance. Enable it by
+setting:
+
+```json5
+{ plugins: { entries: { "voice-call": { enabled: true } } } }
+```
+
+## Notes
+
+- This plugin is a placeholder. Implement your real call flow in the tool and
+  RPC handlers.
+- Use `voicecall.*` for RPC names and `voice_call` for tool naming consistency.