fix(documents): keep deferred imports local and meter every re-send

A document uploaded with aiRead=defer is now indexed locally by any
automatic path, because the indexer reads the marker from the row rather
than from the job. Index all for search leaves such documents out and no
longer counts them. Only an explicit Read with AI or Generate summary ends
the hold.

Uploads that send a body keep their slot of the hourly limit, duplicates
included; handing it back let a token send the same bytes under id after
id for free. One document takes at most 20 further source ids, beyond
which the upload answers 409 documents.inbound.sourceAliasLimit. The
query-string key check is metered on the lookup allowance it shares with
GET /api/documents/inbound/source.

Refs #1038

src/lib/openapi/error-codes.ts

@@ -131,6 +131,7 @@ export const ERROR_CODE_CATALOGUE: Readonly<Record<string, readonly string[]>> =
       "documents.inbound.rateLimited",
       "documents.inbound.restoreDuplicate",
       "documents.inbound.restoreGone",
+      "documents.inbound.sourceAliasLimit",
       "documents.inbound.uploadBusy",
       "documents.inbound.uploadTimeout",
       "documents.inbound.vaccinationNotFound",