feat(13-01): widen SourceType to open union, add NormalizedTenderFields.fingerprint

SourceType now covers 'doe-opendata' | 'ai-netserver' | 'cosinex-dtvp'
(13-RESEARCH Pattern 1) so the Plan 13-04/05 adapters can register
without further type-contract changes. NormalizedTenderFields gains an
optional fingerprint field for the SCHEMA-03 dedup resolver (Plan
13-03) to populate later. tsc --noEmit clean; full API suite green.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/api/src/tenders/tender.types.ts

@@ -8,10 +8,13 @@
 
 /**
  * Identifies which upstream source a raw record originated from.
- * Only 'doe-opendata' exists in this phase (Phase 10); scraping/RSS/email
- * sources are added in later phases (13/14) without changing this contract.
+ * Extended in Phase 13 (13-RESEARCH Pattern 1) from a single-literal type
+ * to an open union so the NetServer (Plan 13-04) and cosinex/DTVP
+ * (Plan 13-05) adapters can be added without further breaking changes.
+ * This union widening is the only breaking type change in Plan 13-01,
+ * and it's contained locally (no runtime behavior change here).
  */
-export type SourceType = 'doe-opendata';
+export type SourceType = 'doe-opendata' | 'ai-netserver' | 'cosinex-dtvp';
 
 /**
  * A single notice as fetched and lightly parsed from a source, before
@@ -80,4 +83,12 @@ export interface NormalizedTenderFields {
   /** sha256(title + deadlineAt + estimatedValue + status) — SCHEMA-02 change-detection hook. */
   contentHash: string;
   publishedAt: Date;
+  /**
+   * SCHEMA-03 (D-04) — cross-source dedup key, computed by tenderFingerprint()
+   * (Plan 13-01 Task 1). Optional here: the normalizer does not set it yet
+   * (that wiring lands in Plan 13-03's dedup resolver) — kept optional so
+   * this additive field doesn't break the Phase-10/11 normalizer contract
+   * before the resolver exists.
+   */
+  fingerprint?: string;
 }