tests(11b): un-quarantine dm-block-filter — hermetic block-list subscription; QUARANTINE now empty

Fully closes #11b's un-quarantine work: the QUARANTINE map is now EMPTY.

dm-block-filter.test.mjs (node:test) PASSED all subtests then hung, so the
node:test runner never exited. Diagnosed via process.getActiveResourcesInfo():
the "integration with loaded user block list" test's manager.loadBlocks() opens a
LIVE block-list subscription through nostrClient's real SimplePool aimed at the
test's fake relay URLs, leaking 4 TCP sockets + reconnect timers. It is NOT the
decrypt-retry timer (verified absent). Nulling nostrClient.pool did not help —
loadBlocks calls ensurePool() (userBlocks.js:967) to re-create+connect a real
pool when pool is falsy.

Fix (node:test-SAFE, no force-exit): make the test hermetic — (1) a TRUTHY stub
pool so ensurePool() is skipped, (2) a no-op getSubscriptionManager so
startBlockListSubscription opens nothing. The block-merge logic under test still
runs fully through the already-stubbed fetchListIncrementally. Restored in finally.
Verified BOTH directions: a clean run exits 0 (# pass 12), AND a deliberately
broken assertion still exits 1 (# fail 1) — failures are NOT masked. A force
process.exit in an after() hook was rejected precisely because it masked failures
(process.exitCode isn't set when the hook fires). See TEST_INTEGRITY.md.

NOTE: the full suite still has one SEPARATE, pre-existing red unrelated to #11b —
tests/ui/uploadModal-reset.test.mjs (TODO #11): its "zombie callbacks" subtest
feeds a plain object where webtorrent expects a Blob ("must be an instance of
Blob") and leaks async activity after the test ends. Untouched here; tracked
under #11 (harden flaky tests), not the #11b quarantine work.

Co-Authored-By: Claude Opus 4.8 <[email protected]>

scripts/run-unit-tests.mjs

@@ -13,9 +13,7 @@ process.env.NODE_ENV = "test";
 // imported `node:test`, silently excluding ~20 bare-assert files; several were
 // failing on main, unnoticed). Each entry MUST cite why and link the triage item.
 // Remove an entry as soon as its file is fixed. See todo/TODO_2026-06-20_pre-launch.md todo-11b.
-const QUARANTINE = new Map([
-  ["tests/dm-block-filter.test.mjs", "HANG (post-completion) — all subtests PASS (TAP 'ok'), then the process hangs on a lingering handle from the imported app stack (nostrService/userBlocks/nostrClient/relayManager) so node:test never exits. Surfaced 2026-07-05 by running the full suite with UNIT_TEST_TIMEOUT_MS (pre-existing; it was never in this map). Needs a node:test-SAFE fix: close the leaked resource in an after() hook so node exits naturally — a force `process.exit` in after() is UNSAFE here (process.exitCode isn't set yet, verified, so it masks real failures). triage todo-11b"],
-]);
+const QUARANTINE = new Map([]);
 
 const rootDir = path.dirname(fileURLToPath(new URL("../package.json", import.meta.url)));
 const testsDir = path.join(rootDir, "tests");