chore: remove metaId fallback from AwsQldbLedger after backfill

[Copilot]

All QLDB documents have been backfilled with an explicit entryId field, so the metaId fallback code path introduced for backward compatibility with pre-migration documents can be removed.

AwsQldbLedger.kt

• resolveEntryId() — drops the metaId fallback branch; now reads entryId directly or returns ""
• getHistory() query — removes h.metadata.id AS metaId projection; only h.metadata.txTime AS txTime and h.data.* are selected

// Before
internal fun resolveEntryId(struct: IonStruct): String =
    (struct.get("entryId") as? IonText)?.stringValue()
        ?: (struct.get("metaId") as? IonText)?.stringValue()
        ?: ""

// After
internal fun resolveEntryId(struct: IonStruct): String =
    (struct.get("entryId") as? IonText)?.stringValue() ?: ""

AwsQldbLedgerEntryResolutionTest.kt

• Removes the two tests that validated metaId fallback behaviour (falls back to metaId when entryId is missing, ignores non-IonText entryId field and falls back to metaId)
• Updates remaining resolveEntryId tests to no longer reference metaId
• Adds resolveEntryId returns empty string when entryId is not an IonText to retain type-mismatch coverage without the fallback expectation

[Copilot]

Pull request overview

This PR removes the backward-compatibility metaId fallback in the QLDB ledger adapter after a production backfill ensured all documents now carry an explicit entryId.

Changes:

• Remove metaId projection from the QLDB history(FactLedger) query.
• Simplify resolveEntryId() to only read entryId (or return empty string).
• Update/trim tests to drop metaId fallback expectations while keeping type-mismatch coverage.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
backend/src/main/kotlin/com/factstore/adapter/outbound/AwsQldbLedger.kt	Removes metaId projection and drops metaId fallback in resolveEntryId() used by history reads.
backend/src/test/kotlin/com/factstore/adapter/outbound/AwsQldbLedgerEntryResolutionTest.kt	Updates tests to align with removal of metaId fallback and keeps coverage for missing/wrong-typed entryId.

[Copilot]

getHistory() now relies solely on the explicit entryId. If production data is not fully backfilled (or a future write omits entryId), this will silently create LedgerEntry objects with entryId == "", which can break clients and makes diagnosing the bad document difficult. Consider failing fast (e.g., throw/log and skip the revision) when resolveEntryId(struct) returns blank, so incomplete backfills are detected immediately rather than producing invalid entries.

Suggested change

	val resolvedEntryId = resolveEntryId(struct)
	val resolvedEntryId = resolveEntryId(struct)
	if (resolvedEntryId.isBlank()) {
	log.error(
	"QLDB history revision for record {} is missing required entryId: {}",
	recordId,
	struct
	)
	throw IllegalStateException("QLDB history revision for record $recordId is missing required entryId")
	}