feat: add programmatic alerting for worker lifecycle events (#16) (#17)

Adds notification system for full visibility into the DevClaw pipeline:

Events and targets:
- workerStart: Posted to project group when worker spawns/resumes
- workerComplete: Posted to project group when DEV done/QA pass/fail/refine
- heartbeat: Posted to orchestrator DM with tick summary

Implementation:
- New lib/notify.ts module with buildMessage() and sendMessage()
- Integrated into task_pickup, task_complete, and heartbeat_tick
- Uses OpenClaw gateway to invoke message tool

Configuration (optional):
- orchestratorDm: Chat ID for heartbeat notifications
- notifications.heartbeatDm: Enable/disable heartbeat DM (default: true)
- notifications.workerStart: Enable/disable start notifications (default: true)
- notifications.workerComplete: Enable/disable completion notifications (default: true)

Notifications fail silently (logged but don't break main flow).

lib/tools/task-complete.ts

@@ -25,6 +25,7 @@ import {
   readProjects,
 } from "../projects.js";
 import type { ToolContext } from "../types.js";
+import { notify, getNotificationConfig } from "../notify.js";
 
 const execFileAsync = promisify(execFile);
 
@@ -266,6 +267,42 @@ export function createTaskCompleteTool(api: OpenClawPluginApi) {
         output.announcement = `🤔 QA REFINE #${issueId}${summary ? ` — ${summary}` : ""}. Awaiting human decision.`;
       }
 
+      // Send notification to project group
+      const pluginConfig = api.pluginConfig as Record<string, unknown> | undefined;
+      const notifyConfig = getNotificationConfig(pluginConfig);
+      
+      // Determine next state for the notification
+      let nextState: string | undefined;
+      if (role === "dev" && result === "done") {
+        nextState = "QA queue";
+      } else if (role === "qa" && result === "pass") {
+        nextState = "Done!";
+      } else if (role === "qa" && result === "fail") {
+        nextState = "back to DEV";
+      } else if (role === "qa" && result === "refine") {
+        nextState = "awaiting human decision";
+      }
+
+      await notify(
+        {
+          type: "workerComplete",
+          project: project.name,
+          groupId,
+          issueId,
+          role,
+          result,
+          summary,
+          nextState,
+        },
+        {
+          workspaceDir,
+          config: notifyConfig,
+          groupId,
+          // Channel detection: default to telegram if not available
+          channel: "telegram",
+        },
+      );
+
       // Audit log
       await auditLog(workspaceDir, "task_complete", {
         project: project.name,