Add lightweight analytics dashboard

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

tests/test_storage.py

@@ -72,3 +72,55 @@ def test_storage_response_fallback_uses_result_when_json_missing(tmp_path: Path)
     assert job is not None
     assert job["response"]["return"] == "Legacy result string"
     assert job["response"]["data"] is None
+
+
+def test_history_db_analytics_groups_by_category_and_day(tmp_path: Path) -> None:
+    db = HistoryDB(tmp_path / "screenjob_test_analytics.db")
+
+    db.create_job(
+        job_id="job_browser_ok",
+        objective="Open amazon.de and checkout",
+        model="gpt-5.4-mini",
+        created_at="2026-05-27T00:00:01Z",
+        safety_override=False,
+        disabled_tools=[],
+    )
+    db.update_job("job_browser_ok", status="completed", steps=4, estimated_cost_usd=0.12)
+
+    db.create_job(
+        job_id="job_browser_fail",
+        objective="Open website and login",
+        model="gpt-5.4-mini",
+        created_at="2026-05-28T00:00:01Z",
+        safety_override=False,
+        disabled_tools=[],
+    )
+    db.update_job("job_browser_fail", status="failed", steps=6, estimated_cost_usd=0.24)
+
+    db.create_job(
+        job_id="job_terminal_ok",
+        objective="Run a shell command to inspect files",
+        model="gpt-5.4-mini",
+        created_at="2026-05-28T00:00:02Z",
+        safety_override=False,
+        disabled_tools=[],
+    )
+    db.update_job("job_terminal_ok", status="completed", steps=10, estimated_cost_usd=0.05)
+
+    analytics = db.analytics()
+    assert analytics["total_jobs"] == 3
+    assert analytics["finished_jobs"] == 3
+    assert analytics["completed_jobs"] == 2
+    assert analytics["failed_jobs"] == 1
+    assert analytics["success_rate"] == 66.67
+    assert analytics["avg_steps"] == 6.67
+    assert analytics["avg_cost_usd"] == 0.136667
+
+    browser = next(row for row in analytics["by_category"] if row["label"] == "Browser / web")
+    terminal = next(row for row in analytics["by_category"] if row["label"] == "Files / terminal")
+    assert browser["finished_jobs"] == 2
+    assert browser["success_rate"] == 50.0
+    assert browser["avg_steps"] == 5.0
+    assert terminal["success_rate"] == 100.0
+
+    assert [row["label"] for row in analytics["timeline"]] == ["2026-05-27", "2026-05-28"]