feat: add live replays and PostgreSQL maintenance tools

- Stream compact live replay updates across local and clustered dashboards.
- Render responsive snake bodies as SVG paths with aligned custom icons.
- Add cache-busted assets, replay fallback routes, and live-follow playback.
- Support PostgreSQL benchmark sampling and idempotent SQLite migration.
- Add dry-run cleanup for old low-quality PostgreSQL replay payloads.
- Reward safe perimeter lanes and bump Prism to version 1.5.0.
- Add backend, migration, dashboard, and perimeter regression coverage.

tests/test_DashboardStaticAssets.py

@@ -0,0 +1,51 @@
+import os
+import re
+import unittest
+
+from server.Server import Server
+
+REPO_ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+
+class TestDashboardStaticAssets(unittest.IsolatedAsyncioTestCase):
+  def setUp(self):
+    self.server = Server(
+      data_path=REPO_ROOT,
+      snake_type='PrismBattleSnake',
+      storage_type='memory',
+      metrics_backend='memory',
+      gameplay_db_enabled=False,
+    )
+
+  def _static_url(self):
+    return self.server.app.jinja_env.globals['static_url']
+
+  async def test_static_url_carries_file_mtime(self):
+    asset = 'js/GameBoard.js'
+    expected_version = int(os.path.getmtime(
+      os.path.join(self.server.app.static_folder, asset)
+    ))
+
+    async with self.server.app.test_request_context('/dashboard'):
+      url = self._static_url()(asset)
+
+    self.assertEqual(url, f'/files/{asset}?v={expected_version}')
+
+  async def test_static_url_tolerates_missing_asset(self):
+    async with self.server.app.test_request_context('/dashboard'):
+      url = self._static_url()('js/DoesNotExist.js')
+
+    self.assertEqual(url, '/files/js/DoesNotExist.js?v=0')
+
+  async def test_dashboard_page_versions_every_static_asset(self):
+    client = self.server.app.test_client()
+    response = await client.get('/dashboard')
+    self.assertEqual(response.status_code, 200)
+    body = await response.get_data(as_text=True)
+
+    references = re.findall(r'(?:href|src)="(/files/[^"]+)"', body)
+    self.assertTrue(references, 'dashboard page referenced no static assets')
+    for reference in references:
+      self.assertRegex(reference, r'\?v=\d+$', f'unversioned static asset: {reference}')
+
+if __name__ == '__main__':
+  unittest.main()