tests: fix two-tab collab baseline race + build the jspi harnesses in CI

1) pcbnew/eeschema two-tab 'a local move propagates A->B' read the
   pre-move baseline AFTER kicadCollabTestMoveFirst. The move is queued
   through CallAfter + the apply coroutine, and the drain can land
   between two consecutive page.evaluate round-trips — when it does
   (~50% under CI load, reproduced locally with --repeat-each) orig
   captures the ALREADY-MOVED position and the not-toBe poll waits on
   itself. Wire tracing showed the bridge working: the moved delta
   emits, nothing reverts. Fix: baseline from kicadCollabSnapshot
   BEFORE the move. 12/12 green at --repeat-each=4 (was ~50% red).

2) jspi-firefox suites 404'd their harness modules: jspi-stack and
   jspi-coroutine build via ad-hoc build.sh (Phase 3 Makefile wiring
   TODO) which CI never ran. Wire both into build-wasm-test.sh (its
   hash is already in the testapps cache key), and add the _pt pthread
   variant that index.html?pt=1 loads but nothing built. jspi-firefox
   8/8 green locally.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PmR6goSk7JC17h7fkgGvHG

scripts/build-wasm-test.sh

@@ -117,6 +117,19 @@ fi
 echo ""
 echo "=== Build complete ==="
 
+# JSPI micro-harnesses (jspi-stack, jspi-coroutine): still on their ad-hoc
+# per-directory build.sh scripts (Makefile.wasm wiring is the Phase 3 TODO).
+# Without this the jspi/ Playwright suites 404 their built .mjs modules on any
+# machine that never ran the scripts by hand — which is exactly what CI is.
+if [ -z "$TARGET" ]; then
+    echo ""
+    echo "=== JSPI micro-harnesses ==="
+    for harness in jspi-stack jspi-coroutine; do
+        echo "Building $harness..."
+        "$STANDALONE_DIR/$harness/build.sh"
+    done
+fi
+
 if [ -n "$TARGET" ]; then
     # Show just the built target
     echo ""