docs(mollifier): fix stale ZSET comments and strip residual plan-doc labels

The mollifier queue moved from ZSET to LIST in an earlier refactor, but two
comments still described it as a ZSET (`mollifierStaleSweep.server.ts:9` and
`env.server.ts:1104` — both narrating the periodic stale sweep). Update to
LIST.

Also clean four residual internal plan-doc labels left over from prior cleanup
passes:

- `createCancelledRun` docstring (`engine/index.ts`) referenced "Q4 mollifier-
  cancel design" and "F4 bypass" — both dead nomenclature now that the gate's
  C1/C3/F4 labels have been rewritten. Restate the waitpoint-skip rationale
  in plain English: the mollifier gate refuses to buffer triggerAndWait
  children, so a cancelled buffered run never has a waiting parent to unblock.
- `createCancelledRun.test.ts` empty-tags regression dropped "Found while
  running the Phase F challenge suite." — the comment describes the bug
  itself, which is self-contained.
- `mollifierStaleSweep.test.ts` "scans across multiple orgs" rephrased away
  from "Phase-3 design has org-level fairness"; the prose now states the
  invariant directly.

Comment/docstring-only; no behaviour change.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: d-cs

apps/webapp/app/env.server.ts

@@ -1101,7 +1101,7 @@ const EnvironmentSchema = z
     TRIGGER_MOLLIFIER_DRAIN_MAX_ATTEMPTS: z.coerce.number().int().positive().default(3),
     TRIGGER_MOLLIFIER_DRAIN_SHUTDOWN_TIMEOUT_MS: z.coerce.number().int().positive().default(30_000),
     TRIGGER_MOLLIFIER_DRAIN_MAX_ORGS_PER_TICK: z.coerce.number().int().positive().default(500),
-    // Periodic sweep that scans buffer queue ZSETs for entries whose
+    // Periodic sweep that scans buffer queue LISTs for entries whose
     // dwell exceeds the stale threshold. Independent of the drainer —
     // its job is exactly to make a stuck/offline drainer visible to
     // ops. Defaults: enabled when the mollifier is enabled, run every

apps/webapp/app/v3/mollifier/mollifierStaleSweep.server.ts

@@ -6,7 +6,7 @@ import {
   reportStaleEntrySnapshot as defaultReportStaleEntrySnapshot,
 } from "./mollifierTelemetry.server";
 
-// One pass of the sweep scans every env's queue ZSET. The per-env page
+// One pass of the sweep scans every env's queue LIST. The per-env page
 // is bounded so a single pathological env can't make the sweep run
 // unboundedly long.
 const DEFAULT_MAX_ENTRIES_PER_ENV = 1000;

apps/webapp/test/mollifierStaleSweep.test.ts

@@ -206,10 +206,11 @@ describe("runStaleSweepOnce — testcontainers", () => {
     "scans across multiple orgs",
     { timeout: 20_000 },
     async ({ redisOptions }) => {
-      // Phase-3 design has org-level fairness in the drainer; the sweep
-      // must walk every org/env, not just the first one it finds. If a
-      // future refactor collapsed listOrgs/listEnvsForOrg into a single
-      // env-flat list this test catches a regression there.
+      // The drainer pops with org-level fairness, so the sweep must
+      // walk every org/env to surface stale entries across all of them
+      // — not just stop at the first env it finds. If a future refactor
+      // collapsed listOrgs/listEnvsForOrg into a single env-flat list,
+      // this test catches a regression there.
       const buffer = new MollifierBuffer({ redisOptions });
       try {
         await buffer.accept({

internal-packages/run-engine/src/engine/index.ts

@@ -453,13 +453,14 @@ export class RunEngine {
   /**
    * Writes a TaskRun row in CANCELED state directly, bypassing the trigger
    * pipeline. Used by the mollifier drainer when a cancel API call lands on
-   * a buffered run before it materialises (Q4 mollifier-cancel design).
+   * a buffered run before it materialises.
    *
-   * Skips: queue insertion (no execution), waitpoint creation (single-
-   * triggerAndWait can't enter the buffer; F4 bypass), concurrency
-   * reservation. Emits `runCancelled` so the existing TaskEvent handler
-   * writes the cancellation event row — the only side effect PG-side cancel
-   * has today per audit.
+   * Skips: queue insertion (no execution), waitpoint creation (the
+   * mollifier gate refuses to buffer triggerAndWait children, so a
+   * cancelled buffered run never has a waiting parent to unblock),
+   * concurrency reservation. Emits `runCancelled` so the existing
+   * TaskEvent handler writes the cancellation event row — the only side
+   * effect PG-side cancel has today per audit.
    *
    * Idempotent: if a row with the same friendlyId already exists (double
    * drainer pop after requeue), Prisma's P2002 unique-constraint violation

internal-packages/run-engine/src/engine/tests/createCancelledRun.test.ts

@@ -191,7 +191,7 @@ describe("RunEngine.createCancelledRun", () => {
   // Prisma misread the object as a relation update op and threw
   // `Argument 'set' is missing`. The drainer caught the error and
   // marked the buffer entry FAILED — so the CANCELED PG row never
-  // landed. Found while running the Phase F challenge suite.
+  // landed.
   containerTest(
     "tolerates snapshot.tags being an empty object (cjson edge case)",
     async ({ prisma, redisOptions }) => {