Add self-contained e2e test harness with ephemeral PocketBase

Previously, 15 e2e tests were skipped because TEST_USER_EMAIL and
TEST_USER_PASSWORD env vars weren't set. Now the test harness:

- Starts a fresh PocketBase instance in /tmp on port 8091
- Creates admin user, collections, and API rules automatically
- Seeds test user with period data for authenticated tests
- Cleans up temp directory after tests complete

Also fixes:
- Override toggle tests now use checkbox role (not button)
- Adds proper wait for OVERRIDES section before testing toggles
- Suppresses document.cookie lint warning with explanation

Test results: 64 e2e tests pass, 1014 unit tests pass

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

e2e/global-teardown.ts

@@ -0,0 +1,54 @@
+// ABOUTME: Playwright global teardown - stops PocketBase and cleans up temp data.
+// ABOUTME: Runs after all e2e tests to ensure clean shutdown.
+import * as fs from "node:fs";
+import * as path from "node:path";
+
+const STATE_FILE = path.join(__dirname, ".harness-state.json");
+
+interface HarnessStateFile {
+  dataDir: string;
+  url: string;
+  pid: number;
+}
+
+export default async function globalTeardown(): Promise<void> {
+  console.log("Stopping PocketBase...");
+
+  // Read the saved state
+  if (!fs.existsSync(STATE_FILE)) {
+    console.log("No harness state file found, nothing to clean up.");
+    return;
+  }
+
+  const state: HarnessStateFile = JSON.parse(
+    fs.readFileSync(STATE_FILE, "utf-8"),
+  );
+
+  // Kill the PocketBase process
+  if (state.pid) {
+    try {
+      process.kill(state.pid, "SIGTERM");
+      // Wait for graceful shutdown
+      await new Promise((resolve) => setTimeout(resolve, 500));
+      // Force kill if still running
+      try {
+        process.kill(state.pid, "SIGKILL");
+      } catch {
+        // Process already dead, which is fine
+      }
+    } catch {
+      // Process might already be dead
+    }
+  }
+
+  // Clean up the temporary data directory
+  if (state.dataDir && fs.existsSync(state.dataDir)) {
+    fs.rmSync(state.dataDir, { recursive: true, force: true });
+    console.log(`Cleaned up temp directory: ${state.dataDir}`);
+  }
+
+  // Remove the state file
+  fs.unlinkSync(STATE_FILE);
+
+  console.log("PocketBase stopped and cleaned up.");
+}