feat: redesign health check to triangulate projects.json, issue label, and session state (#143) (#145)

## Changes

- Remove `activeSessions` parameter from health check (was never populated)
- Add gateway session lookup via `openclaw gateway call status`
- Add issue label lookup via `provider.getIssue(issueId)`
- Implement detection matrix with 6 issue types:
  - session_dead: active worker but session missing in gateway
  - label_mismatch: active worker but issue not in Doing/Testing
  - stale_worker: active for >2h
  - stuck_label: inactive but issue has Doing/Testing label
  - orphan_issue_id: inactive but issueId set
  - issue_gone: active but issue deleted/closed

## Files

- lib/services/health.ts — complete rewrite with three-source triangulation
- lib/tools/health.ts — remove activeSessions param, fetch sessions from gateway
- lib/services/heartbeat.ts — remove empty activeSessions calls, pass sessions map

lib/tools/health.ts

@@ -1,13 +1,21 @@
 /**
  * health — Worker health scan with optional auto-fix.
  *
+ * Triangulates projects.json, issue labels, and session state to detect:
+ *   - session_dead: active worker but session missing in gateway
+ *   - label_mismatch: active worker but issue not in expected label
+ *   - stale_worker: active for >2h
+ *   - stuck_label: inactive but issue has Doing/Testing label
+ *   - orphan_issue_id: inactive but issueId set
+ *   - issue_gone: active but issue deleted/closed
+ *
  * Read-only by default (surfaces issues). Pass fix=true to apply fixes.
  */
 import { jsonResult } from "openclaw/plugin-sdk";
 import type { ToolContext } from "../types.js";
 import { readProjects, getProject } from "../projects.js";
 import { log as auditLog } from "../audit.js";
-import { checkWorkerHealth, type HealthFix } from "../services/health.js";
+import { checkWorkerHealth, fetchGatewaySessions, type HealthFix } from "../services/health.js";
 import { requireWorkspaceDir, resolveProvider } from "../tool-helpers.js";
 
 export function createHealthTool() {
@@ -20,20 +28,21 @@ export function createHealthTool() {
       properties: {
         projectGroupId: { type: "string", description: "Filter to specific project. Omit for all." },
         fix: { type: "boolean", description: "Apply fixes for detected issues. Default: false (read-only)." },
-        activeSessions: { type: "array", items: { type: "string" }, description: "Active session IDs for zombie detection." },
       },
     },
 
     async execute(_id: string, params: Record<string, unknown>) {
       const workspaceDir = requireWorkspaceDir(ctx);
       const fix = (params.fix as boolean) ?? false;
-      const activeSessions = (params.activeSessions as string[]) ?? [];
 
       const groupId = params.projectGroupId as string | undefined;
 
       const data = await readProjects(workspaceDir);
       const projectIds = groupId ? [groupId] : Object.keys(data.projects);
 
+      // Fetch gateway sessions once for all projects
+      const sessions = await fetchGatewaySessions();
+
       const issues: Array<HealthFix & { project: string; role: string }> = [];
 
       for (const pid of projectIds) {
@@ -43,8 +52,13 @@ export function createHealthTool() {
 
         for (const role of ["dev", "qa"] as const) {
           const fixes = await checkWorkerHealth({
-            workspaceDir, groupId: pid, project, role, activeSessions,
-            autoFix: fix, provider,
+            workspaceDir,
+            groupId: pid,
+            project,
+            role,
+            sessions,
+            autoFix: fix,
+            provider,
           });
           issues.push(...fixes.map((f) => ({ ...f, project: project.name, role })));
         }
@@ -55,14 +69,15 @@ export function createHealthTool() {
         fix,
         issuesFound: issues.length,
         issuesFixed: issues.filter((i) => i.fixed).length,
+        sessionsCached: sessions.size,
       });
 
       return jsonResult({
         success: true,
         fix,
         projectsScanned: projectIds.length,
+        sessionsQueried: sessions.size,
         issues,
-        note: activeSessions.length === 0 ? "No activeSessions provided — zombie detection skipped." : undefined,
       });
     },
   });