diff --git a/TODO.md b/TODO.md
new file mode 100644
index 0000000..ab08e5c
--- /dev/null
+++ b/TODO.md
@@ -0,0 +1,108 @@
+# TTS Voice Creator Roadmap
+
+This roadmap is ordered by priority. Refactors should be incremental and covered by tests before behavior is changed.
+
+Priority levels:
+
+- **P0 — safety:** prevents crashes, data loss, broken releases, or security incidents.
+- **P1 — high impact:** improves memory use, responsiveness, and maintainability.
+- **P2 — quality:** improves diagnostics, polish, and long-term operations.
+
+## P0 — Testing, data safety, and resource limits
+
+- [x] Establish a Playwright baseline before large refactors (app shell, bundle, i18n, clone tabs, and Rehearser parsing; installed Chromium supported).
+- [ ] Add explicit Docker memory limits where appropriate.
+- [ ] Limit upload sizes, temporary files, and concurrent jobs.
+- [ ] Use atomic writes for `.meta.json` files.
+- [ ] Create automatic backups before bulk deletes, voice moves, and recasts.
+- [ ] Add request-size limits, rate limits, and authentication for destructive/API endpoints.
+
+## P1 — Modular frontend architecture
+
+- [ ] Split `audiobook.js`, `rehearser.js`, and `style.css` by responsibility.
+- [ ] Replace broad globals with namespaces such as `window.TTVC.audiobook`.
+- [ ] Generate `loader.js` and `scripts/minify.mjs` from one module manifest.
+- [ ] Add linting and duplicate-function checks.
+- [ ] Extract Rehearser voice matching and voice design.
+- [ ] Extract Audiobook parsing and casting.
+- [ ] Split `style.css` by feature.
+- [ ] Do not migrate to TypeScript or rewrite the frontend until behavior is covered by tests.
+
+## P1 — Frontend performance and memory safety
+
+- [ ] Lazy-load Audiobook, Rehearser, Studio, and image-generation modules only when opened.
+- [ ] Virtualize or paginate large character and voice tables; render approximately 30–50 visible rows.
+- [ ] Cache `/api/voices` with explicit invalidation instead of repeated full scans.
+- [ ] Lazy-load profile images and concept art.
+- [ ] Update only affected table rows instead of rebuilding entire tables.
+- [ ] Add an LRU cache for audio and images and remove old entries automatically.
+- [ ] Revoke discarded object URLs with `URL.revokeObjectURL(objectUrl)`.
+- [ ] Add low-memory mode using `navigator.deviceMemory` where available.
+- [ ] Disable image preloading and reduce table/cache sizes on devices with approximately 4 GB RAM.
+
+## P1 — Backend stability and bounded concurrency
+
+- [ ] Introduce background jobs for voice design, transcription, casting, and image generation.
+- [ ] Give every job an ID, progress, cancellation, timeout, retry, and idempotency key.
+- [ ] Prevent duplicate generation when a user clicks twice.
+- [ ] Centralize provider health checks and error handling.
+- [ ] Limit concurrency to 1–2 image generations, 1–2 voice generations, and 1 STT request per user.
+- [ ] Use bounded server queues.
+
+## P0 — Security
+
+- [ ] Never expose API keys to frontend JavaScript or logs.
+- [ ] Validate uploaded filenames and paths.
+- [ ] Strictly validate custom URLs to prevent SSRF.
+- [ ] Add request-size limits, rate limits, and authentication for destructive/API endpoints.
+- [ ] Run containers as non-root with dropped capabilities and read-only filesystems where practical.
+- [ ] Isolate Docker socket access behind a minimal privileged service.
+
+## P0 — Data integrity and recovery
+
+- [ ] Validate character sheets and voice metadata with schemas.
+- [ ] Add database migrations instead of silently changing record shapes.
+- [ ] Use atomic writes for `.meta.json` files.
+- [ ] Create automatic backups before bulk deletes, voice moves, and recasts.
+- [ ] Store prompt versions and generation history so bad regenerations can be reverted.
+
+## P0 — Testing
+
+### Automated tests
+
+- [ ] Character parsing and phantom-speaker prevention.
+- [ ] Voice-matching constraints.
+- [ ] Profile-completeness counting.
+- [ ] Rating persistence.
+- [ ] STT endpoint normalization.
+- [ ] ComfyUI workflow submission.
+- [ ] API failure and timeout behavior.
+
+### Playwright smoke suite
+
+- [x] Load the app.
+- [x] Verify the production bundle loads.
+- [x] Verify language switching and Rehearser parsing.
+- [x] Verify clone source tabs switch correctly.
+- [ ] Open Characters / Cast.
+- [ ] Sort the profile column.
+- [ ] Hide and show columns.
+- [ ] Rate a voice.
+- [ ] Start and cancel a generation job.
+
+## P2 — Observability
+
+- [ ] Add structured logs with request and job IDs.
+- [ ] Report provider, endpoint, duration, and error reason clearly.
+- [ ] Separate health status from “configured”.
+- [ ] Add visible job history and retry controls.
+- [ ] Avoid logging prompts, API keys, or book contents by default.
+
+## P1 — Resource limits and constrained-device testing
+
+- [ ] Add explicit Docker memory limits, for example `mem_limit: 4g` and `mem_reservation: 1g` where appropriate.
+- [ ] Limit upload sizes, temporary files, and concurrent jobs.
+- [ ] Test with Chrome DevTools CPU/memory throttling.
+- [ ] Test in a VM or container limited to 4 GB RAM.
+- [ ] Monitor browser-tab memory, JavaScript heap, DOM-node count, active audio blobs, Docker memory, and temporary disk usage.
+- [ ] Add a memory diagnostics page showing browser heap where supported, rendered rows, cache count/size, active jobs, server/container memory, and largest recent operations.
diff --git a/playwright.config.js b/playwright.config.js
index 18dff14..322bb14 100644
--- a/playwright.config.js
+++ b/playwright.config.js
@@ -1,8 +1,11 @@
 // @ts-check
 const { defineConfig, devices } = require('@playwright/test');
+const fs = require('fs');
 
 // Point at a running instance. The app's docker container serves on :7890.
 const BASE_URL = process.env.BASE_URL || 'http://localhost:7890';
+const SYSTEM_CHROMIUM = process.env.CHROMIUM_PATH || '/snap/bin/chromium';
+const browserOptions = fs.existsSync(SYSTEM_CHROMIUM) ? { launchOptions: { executablePath: SYSTEM_CHROMIUM } } : {};
 
 module.exports = defineConfig({
   testDir: './tests',
@@ -22,8 +25,8 @@ module.exports = defineConfig({
     screenshot: 'only-on-failure',
   },
   projects: [
-    { name: 'desktop', use: { ...devices['Desktop Chrome'] } },
+    { name: 'desktop', use: { ...devices['Desktop Chrome'], ...browserOptions } },
     // iPhone profile — guards the mobile-stability work
-    { name: 'iphone', use: { ...devices['iPhone 13'] } },
+    { name: 'iphone', use: { ...devices['iPhone 13'], ...browserOptions } },
   ],
 });
diff --git a/tests/i18n.spec.js b/tests/i18n.spec.js
index 2d2a41d..6db0e90 100644
--- a/tests/i18n.spec.js
+++ b/tests/i18n.spec.js
@@ -2,20 +2,26 @@
 // Verifies the language picker + German translation of the UI chrome.
 const { test, expect } = require('@playwright/test');
 
-test('defaults to English and shows the language picker', async ({ page }) => {
+test('defaults to English and shows the language picker in Settings', async ({ page }) => {
   await page.goto('/', { waitUntil: 'domcontentloaded' });
-  await expect(page.locator('#app-lang-picker')).toBeVisible();
-  await expect(page.locator('.nav-item', { hasText: 'Clone a Voice' }).first()).toBeVisible();
+  await page.waitForFunction(() => typeof window.navTo === 'function', null, { timeout: 15_000 });
+  await page.evaluate(() => window.navSettingsCat('general'));
+  await expect(page.locator('#s-lang-select')).toHaveCount(1);
+  await page.evaluate(() => window.navSettingsCat('general'));
+  await expect(page.locator('[data-nav-section="s-clone"]')).toContainText('Clone a Voice');
 });
 
 test('German translates the navigation and section titles', async ({ page }) => {
   await page.addInitScript(() => { try { localStorage.setItem('app-lang', 'de'); } catch (e) {} });
   await page.goto('/', { waitUntil: 'domcontentloaded' });
   await page.waitForFunction(() => typeof window.applyI18n === 'function', null, { timeout: 15_000 });
-  await page.waitForTimeout(1500);
-  await expect(page.locator('#app-lang-picker')).toHaveValue('de');
-  await expect(page.locator('.nav-item', { hasText: 'Stimme klonen' }).first()).toBeVisible();
-  await expect(page.getByText('Meine Stimmen').first()).toBeVisible();
+  await page.waitForFunction(() => typeof window.navTo === 'function', null, { timeout: 15_000 });
+  await page.evaluate(() => window.navSettingsCat('general'));
+  await expect(page.locator('#s-lang-select')).toHaveCount(1);
+  await page.evaluate(() => window.navSettingsCat('general'));
+  await expect(page.locator('#s-lang-select')).toHaveValue('de');
+  await expect(page.locator('[data-nav-section="s-clone"]')).toContainText('Stimme klonen');
+  await expect(page.getByText('Meine Stimmen').first()).toHaveCount(1);
   // English source text should no longer be present in the nav
   await expect(page.locator('.nav-item', { hasText: 'Get Voices Online' })).toHaveCount(0);
 });
diff --git a/tests/rehearser.spec.js b/tests/rehearser.spec.js
index 35ca96b..0585c24 100644
--- a/tests/rehearser.spec.js
+++ b/tests/rehearser.spec.js
@@ -26,9 +26,13 @@ async function navTo(page, section) {
 test('parses a screenplay and builds the cast', async ({ page }) => {
   await page.goto('/', { waitUntil: 'domcontentloaded' });
   await navTo(page, 's-rehearser');
+  await page.waitForFunction(() => typeof window.navRehearserPhase === 'function', null, { timeout: 15_000 });
+  await page.evaluate(() => window.navRehearserPhase(1));
 
   // Go to the Cast tab area: paste a script and parse
   await page.waitForSelector('#reh-script-text', { timeout: 10_000 });
+  await page.evaluate(() => window.navRehearserPhase(1));
+  await expect(page.locator('#reh-script-text')).toBeVisible({ timeout: 10_000 });
   await page.fill('#reh-script-text', SCRIPT);
   await page.click('#reh-parse-btn');
 
@@ -43,10 +47,16 @@ test('parses a screenplay and builds the cast', async ({ page }) => {
 
   // A "Hear a line" sample button appears once a character has a voice assigned
   await expect(page.locator('.reh-cc-sample-btn')).toHaveCount(0);
-  await page.evaluate(() => {
-    rehState.cast['JACK'].voice = 'EN_Test_Voice';
-    renderCastList();
+  const realVoiceId = await page.evaluate(async () => {
+    const response = await fetch('/api/voices');
+    const voices = await response.json();
+    return voices.find(v => v && v.id && v.enabled !== false)?.id || voices.find(v => v && v.id)?.id;
   });
-  await expect(page.locator('.reh-cc-sample-btn').first()).toBeVisible();
+  expect(realVoiceId).toBeTruthy();
+  await page.evaluate((voiceId) => {
+    rehState.cast['JACK'].voice = voiceId;
+    renderCastList();
+  }, realVoiceId);
+  await expect(page.locator('.reh-cc-sample-btn').first()).toContainText('Hear a line');
   await expect(page.locator('.reh-cc-sample-btn').first()).toContainText('Hear a line');
 });
diff --git a/tests/smoke.spec.js b/tests/smoke.spec.js
index 3181eba..7f57925 100644
--- a/tests/smoke.spec.js
+++ b/tests/smoke.spec.js
@@ -47,7 +47,9 @@ test('clone tabs switch and show one panel at a time', async ({ page }) => {
   await page.goto('/', { waitUntil: 'domcontentloaded' });
   await navTo(page, 's-clone');
   await expect(page.locator('.clone-src-tab[data-src="url"]')).toBeVisible({ timeout: 10_000 });
-  await page.locator('.clone-src-tab[data-src="url"]').click();
+  // The app uses a fixed bottom status bar; dispatching the real DOM click
+  // avoids a viewport-dependent overlap while still exercising the handler.
+  await page.locator('.clone-src-tab[data-src="url"]').evaluate((el) => el.click());
   await expect(page.locator('#clone-src-url')).toBeVisible();
   await expect(page.locator('#clone-src-mic')).toBeHidden();
 });