feat(14-03): add EmailAlertAdapter generic extraction + 'email-alert' normalizer dispatch

GREEN phase (TDD) for Task 1: extractCandidateLinks (cheerio a[href] +
footer-noise filter + MAX_LINKS_PER_EMAIL cap, plaintext regex fallback),
titleFromEmail (subject -> first body line -> fallback), and
sourceNoticeIdFor (sha256 link hash) implement D-04's generic, no-portal-
specific-parser evaluation of alert emails.

SourceType gains 'email-alert'; TenderNormalizerService routes it through
the existing normalizeBag() path (same as ai-netserver/cosinex-dtvp/rss).
EmailAlertAdapter.fetchTenders() is a Task-1 placeholder — Task 2 wires the
real per-tenant fan-out.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

apps/api/src/tenders/tender-normalizer.service.ts

@@ -55,6 +55,7 @@ export class TenderNormalizerService {
       case 'ai-netserver':
       case 'cosinex-dtvp':
       case 'rss':
+      case 'email-alert':
         return this.normalizeBag(raw);
       case 'doe-opendata':
       default:
@@ -118,13 +119,14 @@ export class TenderNormalizerService {
 
   /**
    * Generic-bag path (gap closure): NetServer/cosinex-DTVP scraper adapters
-   * (and, since Phase 14 Plan 02, the RssAdapter, INGEST-04) carry a flat
+   * (and, since Phase 14 Plan 02, the RssAdapter, INGEST-04; and since
+   * Phase 14 Plan 03, the EmailAlertAdapter, INGEST-05) carry a flat
    * `{title, buyerName, procedureType, legalFramework, deadlineAt}` bag in
    * `raw.ocdsPayload` — there is no eForms/OCDS structure to inspect.
    * `legalFramework` is deliberately NOT mapped: NormalizedTenderFields has
-   * no target field for it. RSS records always have `buyerName`/
-   * `procedureType`/`deadlineAt` null (baseline title/link/guid mapping
-   * only, D-04/D-05 thin-fields deferral).
+   * no target field for it. RSS/email-alert records always have
+   * `buyerName`/`procedureType`/`deadlineAt` null (baseline title/link/guid
+   * mapping only, D-04/D-05 thin-fields deferral).
    */
   private normalizeBag(raw: RawTenderRecord): NormalizedTenderFields {
     const bag = getBagPayload(raw.ocdsPayload);