perf(dashboard): slim task list + auto-archive stale done tasks

GET /api/tasks was returning ~69 MB of JSON per call (67.9 MB of agent
logs across 1199 tasks), causing the dashboard to hang for 2+ minutes.

- core: extend listTasks() with slim and includeArchived options
- dashboard: GET /api/tasks now uses slim mode and excludes archived
  by default; ?includeArchived=1 opts in
- frontend: lazy-load archived tasks when the archived column is first
  expanded via new useTasks.loadArchivedTasks()
- engine: self-healing maintenance now auto-archives done tasks older
  than 48h (data stays in SQLite, column flips done -> archived)
- tests: slim mode + includeArchived coverage in store.test.ts;
  routes.test.ts assertion updated for new args

Also bundles in-progress test-setup noise filters and pre-existing
QuickEntryBox/routes test work that was already modified locally.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/core/src/store.test.ts

@@ -1322,6 +1322,42 @@ describe("TaskStore", () => {
       expect(paged).toHaveLength(1);
       expect(paged[0].id).toBe("FN-002");
     });
+
+    it("slim mode returns metadata but drops heavy fields (log/comments/steps)", async () => {
+      const task = await store.createTask({ description: "Slim test" });
+      await store.logEntry(task.id, "heavy log entry that should not appear in slim list");
+
+      const fullList = await store.listTasks();
+      const slimList = await store.listTasks({ slim: true });
+
+      const full = fullList.find((t) => t.id === task.id)!;
+      const slim = slimList.find((t) => t.id === task.id)!;
+
+      expect(full.log.length).toBeGreaterThan(0);
+      expect(slim.id).toBe(task.id);
+      expect(slim.description).toBe("Slim test");
+      expect(slim.column).toBe(full.column);
+      expect(slim.log).toEqual([]);
+      expect(slim.steps).toEqual([]);
+      expect(slim.comments).toBeUndefined();
+    });
+
+    it("includeArchived=false excludes archived tasks; default includes them", async () => {
+      const keep = await store.createTask({ description: "Stays visible" });
+      const toArchive = await store.createTask({ description: "Will be archived" });
+      await store.moveTask(toArchive.id, "todo");
+      await store.moveTask(toArchive.id, "in-progress");
+      await store.moveTask(toArchive.id, "in-review");
+      await store.moveTask(toArchive.id, "done");
+      await store.archiveTask(toArchive.id);
+
+      const withArchived = await store.listTasks();
+      const withoutArchived = await store.listTasks({ includeArchived: false });
+
+      expect(withArchived.map((t) => t.id)).toEqual(expect.arrayContaining([keep.id, toArchive.id]));
+      expect(withoutArchived.map((t) => t.id)).toContain(keep.id);
+      expect(withoutArchived.map((t) => t.id)).not.toContain(toArchive.id);
+    });
   });
 
   describe("SQLite-first reads when task blobs are missing", () => {

packages/core/src/store.ts

@@ -1307,8 +1307,39 @@ export class TaskStore extends EventEmitter<TaskStoreEvents> {
     return { ...task, prompt };
   }
 
-  async listTasks(options?: { limit?: number; offset?: number }): Promise<Task[]> {
-    const rows = this.db.prepare('SELECT * FROM tasks ORDER BY createdAt ASC').all();
+  async listTasks(options?: {
+    limit?: number;
+    offset?: number;
+    /** When false, exclude tasks in the `archived` column. Default: true (backward compatible). */
+    includeArchived?: boolean;
+    /** When true, omit heavy fields (log, comments, steps, workflowStepResults, steeringComments)
+     *  from each row to make list responses cheap for board-style consumers. Detail fields default
+     *  to empty arrays in the returned Task objects; use `getTask(id)` to load full data. */
+    slim?: boolean;
+  }): Promise<Task[]> {
+    const includeArchived = options?.includeArchived ?? true;
+    const slim = options?.slim ?? false;
+
+    const slimColumns = `
+      id, title, description, "column", status, size, reviewLevel, currentStep,
+      worktree, blockedBy, paused, baseBranch, branch, baseCommitSha,
+      modelPresetId, modelProvider, modelId,
+      validatorModelProvider, validatorModelId,
+      planningModelProvider, planningModelId,
+      mergeRetries, stuckKillCount, recoveryRetryCount, nextRecoveryAt,
+      error, summary, thinkingLevel,
+      createdAt, updatedAt, columnMovedAt,
+      dependencies,
+      attachments, prInfo, issueInfo, mergeDetails,
+      breakIntoSubtasks, enabledWorkflowSteps, modifiedFiles,
+      missionId, sliceId, assignedAgentId, assigneeUserId,
+      checkedOutBy, checkedOutAt
+    `;
+    const selectClause = slim ? slimColumns : '*';
+    const whereClause = includeArchived ? '' : ` WHERE "column" != 'archived'`;
+    const sql = `SELECT ${selectClause} FROM tasks${whereClause} ORDER BY createdAt ASC`;
+
+    const rows = this.db.prepare(sql).all();
     const tasks = (rows as any[]).map((row) => this.rowToTask(row));
 
     // Sort by createdAt, then by numeric ID suffix for tie-breaking