storage-cors-4: guard obsolete registered feed completions; close landed storage-cors-3

docs/testing/storage-cors-4-integrity.md

@@ -0,0 +1,38 @@
+# storage-cors-4 registered lifecycle integrity
+
+```yaml
+test_integrity_note:
+  change_type: ["new_tests"]
+  scenarios:
+    - id: SCN-storage4-registered-completion
+      given: "Real registered Recent/Explore/For You pipelines and real JSDOM VideoListView/Card, with controlled moderation subscription IO"
+      when: "Older success or rejection resolves after a newer refresh, deletion, empty result, feed replacement, or disposal"
+      then: "Only eligible current request changes DOM, metadata, telemetry and presentation effects; stale caller still settles"
+    - id: SCN-storage4-current-controls
+      given: "A current registered pipeline or fallback and a live view"
+      when: "History or moderation IO is delayed, engine fails, or engine is unavailable"
+      then: "Live cards/fallback and metadata remain observable with natural completion"
+    - id: SCN-storage4-obsolete-load
+      given: "Retained onVideos callback or history preload belongs to replaced load"
+      when: "Same-feed replacement or different-feed load wins"
+      then: "Old callback starts no refresh; obsolete runtime starts no engine or presentation effects"
+  observable_outcomes:
+    - "Card DOM IDs, view container ownership, payloads, metadata identity, render/impression counts and telemetry calls"
+  determinism_controls:
+    - "Explicit deferred IO; synthetic offline events, fake subscription/storage adapters; no sleeps/retries/timeouts"
+  anti_cheat_rationale:
+    prevents:
+      - "hard-coded empty output via delayed/current/fallback controls"
+      - "decorator-only pipeline replacement via actual registered production stages"
+      - "success-only guards via delayed rejected engine with telemetry assertions"
+      - "per-feed counters ignoring view replacement via same-feed remount controls"
+  relaxation:
+    did_relax_any_assertion: false
+    if_true_explain_spec_basis: ""
+```
+
+16 retained scenarios in tests/storage-feed-lifecycle.test.mjs. Auto-discovered by unchanged normal runner; no registration bypass. Uses existing actual client/buffer/service fixture, synthetic signatures and controlled adapters. Source, filters, moderation, timestamps, scoring/sorting and actual DOM rendering execute. First moderation setActiveEventIds containing original pauses; no custom decorator stage. Engine error tests wrap real run and reject after its production stages return. History preload exercises actual For You await.
+
+Nine isolated runtime mutants all exit1 naturally, cancelled0; restored in finally. Original coordinator fails12/16; ignoring request order fails4; ignoring view eligibility fails2; ignoring stale errors fails2; ignoring stale runtime fails1; suppressing current rendering fails9; obsolete load callbacks enabled fails1; allowing orphan completion fails11; dropping fallback fails3. Each retained scenario rejects original or a relevant broken control variant. No assertion relaxation or existing-test edit.
+
+Live network/signatures/moderation timing, full application router/auth teardown, native browser and manual release not verified. No new source/cache/deletion policy. Return choice and pre-engine supersession are documented in decisions/DECISIONS_2026-10-22_20-45-00_storage-cors-4.md.