tests: in-run progress strip + cache-bust runner.js across files

* runner.js: shows a 30px fixed-top progress strip during runs (label
  "test x/total:", current suite/test name with ellipsis on the left,
  fixed 50%-wide progress fill on the right that turns danger-red on
  the first failure). The DOM node is created in loader.js so it appears
  immediately on shortcut press; runner.js only updates it. The fill
  width is fixed at flex:0 0 50% so it doesn't jiggle as the test name
  changes length. Suites now live on window._testSuites as a defensive
  fallback so two runner instances stay in sync.

* Cache invalidation: every test file's `from './runner.js'` is now
  `from './runner.js?v=2'`, and loader.js imports the runner with the
  same RUNNER_V suffix. Same URL → one module instance → suite
  registration and runAll see the same array. Bumping RUNNER_V (in
  loader.js + every test file in lock-step) is the way to force a
  re-fetch when runner.js changes.

* loader.js: ensureProgressBar() draws the strip via setProperty(...,
  'important') with z-index 2147483647 attached to documentElement so
  nothing in user CSS, scanline overlay (z 9999) or modals can occlude
  it. Auto-run path (?test=1) also pre-renders the strip.

chore: bump version to 0.9.1

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

public/plugins/tests/canvas.test.js

@@ -1,4 +1,4 @@
-import { describe, it, beforeEach, afterEach, expect, $, click, sleep, closeAll } from './runner.js';
+import { describe, it, beforeEach, afterEach, expect, $, click, sleep, closeAll } from './runner.js?v=2';
 
 // ── Helpers ──