replace Redis with an embedded SQLite string->string KV store (group commit, in-tx events, SQL search)

internal/storage/uuid.go

@@ -8,7 +8,7 @@ import (
 // layout). Used as the root key for file metadata entries.
 //
 // Why this format over canonical 8-4-4-4-12 hex:
-//   - 26 chars vs 36 — shorter Redis keys, less prefix space waste
+//   - 26 chars vs 36 — shorter keys, less prefix space waste
 //   - Time-sortable prefix — KEYS file:01JKR* returns entries minted in a
 //     given time window, restoring some of the debug-ability lost vs the
 //     previous midhash256:abc rooting