v0.2 Phase 0+1: planning doc + tooling baseline

Phase 0 — docs/release/v0.2-frontend-overhaul.md as single source of
truth for the v0.2 frontend coherence pass. Records hard rules,
tooling pins, sacred-behaviour contract list, wrapper catalogue,
per-page migration order, verification matrix, KI-05 plan, and the
explicit "DO NOT add Skeleton" line.

Phase 1 — tooling baseline. All exact-pinned per the plan:

- @playwright/test@1.60.0 + playwright@1.60.0 + @axe-core/playwright@4.11.3
- rollup-plugin-visualizer@7.0.1 (wired behind ANALYZE=1)
- @vitest/browser@4.1.6 + @vitest/browser-playwright@4.1.6 (provider)
- vitest-browser-svelte@2.1.1 (runes-aware Svelte 5 bridge)
- cargo-nextest installed globally

New configs: playwright.config.ts (frontend-only, dev:frontend webServer,
900x700 + 1440x900 projects, visual baselines deferred), vitest.browser.config.js
(separate from jsdom suite). New scripts: test:e2e, test:e2e:ui,
test:browser, analyze, test:rust:fast, guard:no-skeleton.

guard-no-skeleton.mjs walks package.json + package-lock + src/ for any
@skeletonlabs reference and exits 1 if found — locks in the no-Skeleton
hard rule for any future agent.

Smoke baseline (tests/e2e/smoke.spec.ts): 16 tests passing across two
viewports — app loads without Tauri runtime, keyboard nav, axe scan
(color-contrast deferred to Phase 7 per docs/release/v0.1-contrast-audit.md),
light/dark theme cycle, all three sensory zones (cave/energy/reset).
10 screenshots emitted to test-results/ as non-failing artefacts.

Surfaced + fixed two browser-preview bugs while landing the baseline:

- src/lib/utils/osInfo.ts: FALLBACK_BROWSER_INFO was evaluated at SSR
  module-load (navigator undefined → os: 'unknown'), and the UA check
  ran before navigator.platform — so Playwright's Windows-UA Chromium
  on a Linux runner detected as Windows, useCustomChrome went true,
  Titlebar mounted and tripped Tauri-only APIs. Now lazy-built per
  call; platform is the primary signal, UA only a fallback.

- src/lib/components/Titlebar.svelte: defensive hasTauriRuntime() guard
  on every handler and the $effect. Titlebar should not crash if any
  future code path mounts it without Tauri.

.gitignore: reports/, .playwright/, test-results/, playwright-report/.

Per-phase gate green: npm run check (0/0), npm test (0/0), npm run
test:e2e (16/16), npm run guard:no-skeleton (clean).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

playwright.config.ts

@@ -0,0 +1,39 @@
+import { defineConfig, devices } from "@playwright/test";
+
+// Frontend-only E2E. The dev server is SvelteKit (npm run dev:frontend) on
+// localhost:1420 — Tauri IPC is not present. Tests must not depend on Tauri
+// commands; mock the invoke boundary if you need a Tauri-flavoured surface,
+// or skip the assertion with a reason and cover it via `cargo test` instead.
+//
+// Visual diffs are NOT failing the build yet; screenshots are captured as
+// artifacts. After Phase 7 stabilises the UI, a follow-up commit promotes
+// baselines and enables failing diffs.
+export default defineConfig({
+  testDir: "tests/e2e",
+  fullyParallel: true,
+  forbidOnly: !!process.env.CI,
+  retries: process.env.CI ? 2 : 0,
+  reporter: [["list"], ["html", { open: "never", outputFolder: "playwright-report" }]],
+  outputDir: "test-results",
+  use: {
+    baseURL: "http://localhost:1420",
+    trace: "on-first-retry",
+    screenshot: "only-on-failure",
+  },
+  projects: [
+    {
+      name: "chromium-900x700",
+      use: { ...devices["Desktop Chrome"], viewport: { width: 900, height: 700 } },
+    },
+    {
+      name: "chromium-1440x900",
+      use: { ...devices["Desktop Chrome"], viewport: { width: 1440, height: 900 } },
+    },
+  ],
+  webServer: {
+    command: "npm run dev:frontend",
+    url: "http://localhost:1420",
+    reuseExistingServer: !process.env.CI,
+    timeout: 120_000,
+  },
+});