Electron suite: 4 pre-existing red tests on main (env + fixture drift) #535

Found during the perf pass (thread 693440a8) — all reproduce with the perf diff stashed and are independent of any branch:

1. store.test.js "round-trips projects, threads, messages, work log" — migrateThread injects reviewAcceptedHunks: [] (store.js:798) but the test fixture never expects it. Same failure class as the earlier quota-wait-keys red: migrateThread defaults keep landing without the round-trip fixture being updated. Fails on origin/main (test file byte-identical).
2. web.test.js "package-app.sh copies electron/*.js and node_modules/ws" — test regex expects a literal node_modules/ws in package-app.sh; the script now copies via ROOT_NM_PKGS=(ws cross-spawn ...). Test/script drift on main.
3. checkpoints.test.js "runner auto-checkpoint on successful turn" — throws worktreeBase is not configured from materializePendingWorktree (runner.js:4260). Environment/settings dependent.
4. verify-gate.test.js — 4 subtests red at baseline.

Note: 10 other electron failures seen during the pass were environment rot and are now fixed: the tracked core/dist symlink breakage (main deleted it upstream; rebuilt locally) and missing memory-server node_modules (docs/ISSUES.md already documents the SDK-missing half).