Par2 size matching 100x faster; release bookkeeping once per statement

matchPar2Releases checked every same-size release_files row's set and
date (18 s per batch of body-derived binaries); now an index on
release_files (release_id, size) drops the repeated sizes first: 0.16 s.

File inserts updated their release in four row triggers; one statement
trigger now updates each release once per INSERT. Completeness is noted
in release_dirty and recomputed by gc:scheduler every 30 minutes.

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

commands/GcScheduler.ts

@@ -9,6 +9,7 @@ import IndexMaintenance from '#services/IndexMaintenance'
 import ReleaseMergeService from '#services/ReleaseMergeService'
 import StagingService from '#services/StagingService'
 import FilePartitions from '#services/FilePartitions'
+import ReleaseCompleteness from '#services/ReleaseCompleteness'
 import Shutdown from '#services/Shutdown'
 
 const CLEAN_BATCH = 1000
@@ -30,6 +31,9 @@ export default class GcScheduler extends BaseCommand {
   @flags.boolean({ description: 'Report what would be removed without changing anything' })
   declare dryRun: boolean
 
+  /** When release completeness was last recomputed (it runs less often than the sweep). */
+  private completenessAt = 0
+
   public async run() {
     this.logger.info(
       `GC started (interval ${gcConfig.intervalMs / 1000}s${this.dryRun ? ', dry run' : ''}).`
@@ -42,6 +46,11 @@ export default class GcScheduler extends BaseCommand {
         } catch (err: any) {
           this.logger.error(`GC sweep failed: ${err.message}`)
         }
+        try {
+          await this.releaseCompleteness()
+        } catch (err: any) {
+          this.logger.error(`Release completeness failed: ${err.message}`)
+        }
         if (!this.once) await Shutdown.sleep(gcConfig.intervalMs)
       } while (!this.once && !Shutdown.requested)
     } finally {
@@ -108,6 +117,14 @@ export default class GcScheduler extends BaseCommand {
   }
 
   /** Rebuilds bloated indexes, at most every gcConfig.reindexIntervalMs (CONCEPT.md D33). */
+  private async releaseCompleteness() {
+    if (this.dryRun || (!this.once && Date.now() - this.completenessAt < gcConfig.releaseCompleteIntervalMs)) return
+    this.completenessAt = Date.now()
+    const started = Date.now()
+    const checked = await ReleaseCompleteness.sweep()
+    if (checked > 0) this.logger.info(`Release completeness: ${checked} changed releases checked in ${Math.round((Date.now() - started) / 1000)} s.`)
+  }
+
   private async rebuildIndexes() {
     const key = 'gc:reindex:last'
     const last = Number((await RedisService.client.get(key)) ?? 0)