feat(FN-4748): complete Step 4 — add startup github tracking reconciliation

Fusion-Task-Id: FN-4748
Fusion-Task-Lineage: b540f985-c20f-438e-8290-a07531c6612c

packages/dashboard/src/github-tracking-reconciler.ts

@@ -0,0 +1,76 @@
+import type { GlobalSettings, ProjectSettings, Task, TaskStore } from "@fusion/core";
+import { resolveGithubTrackingAuth } from "./github-auth.js";
+import { GitHubClient } from "./github.js";
+
+const RECONCILE_SCAN_LIMIT = 200;
+const RECONCILE_CONCURRENCY_LIMIT = 4;
+
+export class GitHubTrackingReconciler {
+  async reconcile(store: TaskStore): Promise<{ scanned: number; closed: number; skipped: number; errors: number }> {
+    const tasks = (await store.listTasks({ slim: true, includeArchived: false }))
+      .filter((task) => task.status === "done")
+      .slice(0, RECONCILE_SCAN_LIMIT);
+
+    const projectSettings = await store.getSettings() as Pick<ProjectSettings, "githubAuthMode" | "githubAuthToken">;
+    const globalSettings = (await store.getGlobalSettingsStore?.()?.getSettings?.() ?? {}) as Pick<GlobalSettings, never>;
+    const resolution = resolveGithubTrackingAuth({ projectSettings, globalSettings });
+    if (!resolution.ok) {
+      for (const task of tasks) {
+        await store.logEntry(task.id, "Skipped GitHub tracking issue reconciliation", resolution.message);
+      }
+      return { scanned: tasks.length, closed: 0, skipped: tasks.length, errors: 0 };
+    }
+
+    const client = resolution.auth.mode === "token"
+      ? new GitHubClient({ token: resolution.auth.token, forceMode: "token" })
+      : new GitHubClient({ forceMode: "gh-cli" });
+
+    let closed = 0;
+    let skipped = 0;
+    let errors = 0;
+
+    await runWithConcurrencyLimit(tasks, RECONCILE_CONCURRENCY_LIMIT, async (task) => {
+      const issue = task.githubTracking?.issue;
+      if (task.githubTracking?.enabled !== true || !issue?.owner || !issue.repo || !issue.number) {
+        skipped += 1;
+        return;
+      }
+
+      try {
+        const linkedIssue = await client.getIssue(issue.owner, issue.repo, issue.number);
+        if (!linkedIssue || linkedIssue.state === "closed") {
+          skipped += 1;
+          return;
+        }
+
+        await client.setIssueState(issue.owner, issue.repo, issue.number, "closed", "completed");
+        closed += 1;
+      } catch (error) {
+        errors += 1;
+        await store.logEntry(
+          task.id,
+          "Failed to reconcile GitHub tracking issue",
+          error instanceof Error ? error.message : String(error),
+        );
+      }
+    });
+
+    return { scanned: tasks.length, closed, skipped, errors };
+  }
+}
+
+async function runWithConcurrencyLimit<T>(items: T[], limit: number, worker: (item: T) => Promise<void>): Promise<void> {
+  const queue = [...items];
+  const workers = Array.from({ length: Math.min(limit, items.length) }, async () => {
+    while (queue.length > 0) {
+      const item = queue.shift();
+      if (item !== undefined) {
+        await worker(item);
+      }
+    }
+  });
+
+  await Promise.all(workers);
+}
+
+export { RECONCILE_CONCURRENCY_LIMIT, RECONCILE_SCAN_LIMIT };