refactor(prospecting): migrate SVC-006 transaction control to endpoint level

Move db.commit() from services to API endpoints and Celery tasks.
Services now use db.flush() only; endpoints own the transaction.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/modules/prospecting/routes/api/admin_enrichment.py

@@ -38,6 +38,7 @@ def http_check_single(
     """Run HTTP connectivity check for a single prospect."""
     prospect = prospect_service.get_by_id(db, prospect_id)
     result = enrichment_service.check_http(db, prospect)
+    db.commit()
     return HttpCheckResult(**result)
 
 
@@ -53,6 +54,7 @@ def http_check_batch(
     for prospect in prospects:
         result = enrichment_service.check_http(db, prospect)
         results.append(HttpCheckBatchItem(domain=prospect.domain_name, **result))
+    db.commit()
     return HttpCheckBatchResponse(processed=len(results), results=results)
 
 
@@ -65,6 +67,7 @@ def tech_scan_single(
     """Run technology scan for a single prospect."""
     prospect = prospect_service.get_by_id(db, prospect_id)
     profile = enrichment_service.scan_tech_stack(db, prospect)
+    db.commit()
     return ScanSingleResponse(domain=prospect.domain_name, profile=profile is not None)
 
 
@@ -81,6 +84,7 @@ def tech_scan_batch(
         result = enrichment_service.scan_tech_stack(db, prospect)
         if result:
             count += 1
+    db.commit()
     return ScanBatchResponse(processed=len(prospects), successful=count)
 
 
@@ -93,6 +97,7 @@ def performance_scan_single(
     """Run PageSpeed audit for a single prospect."""
     prospect = prospect_service.get_by_id(db, prospect_id)
     profile = enrichment_service.scan_performance(db, prospect)
+    db.commit()
     return ScanSingleResponse(domain=prospect.domain_name, profile=profile is not None)
 
 
@@ -109,6 +114,7 @@ def performance_scan_batch(
         result = enrichment_service.scan_performance(db, prospect)
         if result:
             count += 1
+    db.commit()
     return ScanBatchResponse(processed=len(prospects), successful=count)
 
 
@@ -121,6 +127,7 @@ def scrape_contacts_single(
     """Scrape contacts for a single prospect."""
     prospect = prospect_service.get_by_id(db, prospect_id)
     contacts = enrichment_service.scrape_contacts(db, prospect)
+    db.commit()
     return ContactScrapeResponse(domain=prospect.domain_name, contacts_found=len(contacts))
 
 
@@ -154,6 +161,7 @@ def full_enrichment(
     # Step 5: Compute score
     db.refresh(prospect)
     score = scoring_service.compute_score(db, prospect)
+    db.commit()
 
     return FullEnrichmentResponse(
         domain=prospect.domain_name,
@@ -174,4 +182,5 @@ def compute_scores_batch(
 ):
     """Compute or recompute scores for all prospects."""
     count = scoring_service.compute_all(db, limit=limit)
+    db.commit()
     return ScoreComputeBatchResponse(scored=count)