feat(MAT-174): Add cron job scheduler and executors

Cron package that syncs jobs from matrixhost portal API, schedules execution
with timezone-aware timing, and posts results to Matrix rooms. Includes
Brave Search, reminder, and browser scrape (placeholder) executors with
formatter. 31 pytest tests.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/test_cron_browser_executor.py

@@ -0,0 +1,58 @@
+"""Tests for the browser scrape executor."""
+
+from unittest.mock import AsyncMock
+
+import pytest
+
+from cron.browser_executor import execute_browser_scrape
+
+
+class TestBrowserScrapeExecutor:
+    @pytest.mark.asyncio
+    async def test_returns_error_without_profile(self):
+        job = {
+            "id": "j1",
+            "name": "FB Scan",
+            "config": {"url": "https://facebook.com/marketplace"},
+            "targetRoom": "!room:test",
+            "browserProfile": None,
+        }
+        send_text = AsyncMock()
+        result = await execute_browser_scrape(job=job, send_text=send_text)
+        assert result["status"] == "error"
+        assert "browser profile" in result["error"].lower()
+        send_text.assert_called_once()
+        msg = send_text.call_args[0][1]
+        assert "matrixhost.eu/settings/automations" in msg
+
+    @pytest.mark.asyncio
+    async def test_returns_error_with_expired_profile(self):
+        job = {
+            "id": "j1",
+            "name": "FB Scan",
+            "config": {"url": "https://facebook.com/marketplace"},
+            "targetRoom": "!room:test",
+            "browserProfile": {"id": "b1", "status": "expired", "name": "facebook"},
+        }
+        send_text = AsyncMock()
+        result = await execute_browser_scrape(job=job, send_text=send_text)
+        assert result["status"] == "error"
+        assert "expired" in result["error"].lower()
+        send_text.assert_called_once()
+        msg = send_text.call_args[0][1]
+        assert "re-record" in msg.lower()
+
+    @pytest.mark.asyncio
+    async def test_placeholder_with_active_profile(self):
+        job = {
+            "id": "j1",
+            "name": "FB Scan",
+            "config": {"url": "https://facebook.com/marketplace"},
+            "targetRoom": "!room:test",
+            "browserProfile": {"id": "b1", "status": "active", "name": "facebook"},
+        }
+        send_text = AsyncMock()
+        result = await execute_browser_scrape(job=job, send_text=send_text)
+        # Currently a placeholder, should indicate not yet implemented
+        assert result["status"] == "error"
+        assert "not yet implemented" in result["error"].lower()