tests: un-skip sweep — 26 tests revived on the JSPI build, failures re-gated with fresh evidence

Empirical pass over every skip/fixme whose premise the JSPI migration
could have changed. Revived (verified green):

- Firefox wasm-budget guards RETIRED (drift-trio, drift-trio-fuzz,
  drift-trio-scenarios, ysync-two-tab, ysync-libsymbols): the JSPI
  build (~half the asyncify size) fits three editor tabs inside
  Firefox 153's per-process budget — +20 firefox collab tests.
- roundtrip 'pcbnew preserves items through a yjs round trip': the
  asyncify-fragile envelope parse it waited on is gone — both engines.
- drift-trio-scenarios S4/S4b: converge now (was KNOWN ~5-8%).
- pcbnew-collab + eeschema-collab 'a local move propagates A→B'.
- web eeschema-fp-selector, read-only-editor's fixme'd writer-stream
  test, footprint-browse-remote read path (chromium; firefox gated:
  FootprintEnumerate rows never appear in 60s — slow wasm tier
  suspected).

Still broken, re-gated with re-verified reasons:

- 3d-viewer raytracer engine toggle: still inert, both engines.
- maximize display geometry: wxDisplay reports 0x0 in the harness.
- web editor WRITE bridge (symbol/footprint × remote/spike): wedges at
  the New Symbol/Footprint dialog step on both engines — the
  web-e2e-rot 01 gap stands for writes.

Verify runs: kicad+wx touched files 93 passed / 0 failed / 7 skipped
(intended gates); web touched files 7 passed / 0 failed / 9 skipped.
lint:determinism + lint:ci-coverage green.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016X9eh1s5sTx1o9Em9KBuwR

tests/web/symbol-write-remote.spec.ts

@@ -21,7 +21,10 @@ const BACKEND = process.env.BACKEND_URL ?? 'http://localhost:3060';
   // KNOWN-BROKEN: the fp/sym editor kicadLibs enumerate/save flows are dead
   // (docs/features/web-e2e-rot/01-editor-lib-bridge-flows.md). fixme, not fail:
   // on CI this dies in a 180s boot timeout per engine — running it buys no signal.
-test.fixme('symbol editor save persists to the backend (remote write round-trip)', async ({ page }) => {
+// Probed 2026-08-13 on the JSPI build: still dead — wedges at the New Symbol/
+// Footprint dialog step on BOTH engines (web-e2e-rot 01 stands for writes).
+test.fixme(
+  'symbol editor save persists to the backend (remote write round-trip)', async ({ page }) => {
   // Unique owner per run so the test is isolated from prior runs.
   const owner = `e2e-${Date.now()}`;
   const logs: string[] = [];