Inspection backlog in Postgres; BullMQ gets a working set

5.4M waiting inspection jobs took 3.3 GB of Redis and most of its single
thread. Producers now add file ids to inspection_queue; index-scheduler
feeds up to INSPECTION_FEED_MAX (50k) into BullMQ. inspection:from-redis
moves the existing backlog over once.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

start/env.ts

@@ -107,6 +107,7 @@ export default await Env.create(new URL('../', import.meta.url), {
   FILE_KEYS_FILL_SECONDS: Env.schema.number.optional(),
   GC_AWAIT_INSPECTION_SECONDS: Env.schema.number.optional(),
   GC_MERGE_INTERVAL_MS: Env.schema.number.optional(),
+  INSPECTION_FEED_MAX: Env.schema.number.optional(),
   ARCHIVE_WALK_MAX_SEGMENTS: Env.schema.number.optional(),
   DEFERRED_SETTLE_MS: Env.schema.number.optional(),
   DEFERRED_EXPAND_MAX_PARTS: Env.schema.number.optional(),