Trim heavy search stages to avoid 504

TODO.md

@@ -341,6 +341,17 @@
 - [ ] full browser-level validation was not fully reproducible in this environment
 
 ## Recent Change Log
+- Date: `2026-03-16`
+- What changed:
+  - Reduced the heaviest search-stage caps slightly: fewer query variants per request, smaller per-source result caps, lower enrichment scope, and a bounded Gemini candidate set.
+- Why it changed:
+  - The widened search configuration was pushing the request past the reverse-proxy timeout and surfacing `504 Gateway Time-out`.
+- How it was verified:
+  - `go test ./...`
+  - `bash scripts/selftest.sh`
+- What is still risky or incomplete:
+  - Search coverage is still broader than the original baseline, but there is now an explicit tradeoff between result volume and request latency.
+
 - Date: `2026-03-16`
 - What changed:
   - Increased collector result caps and widened source-specific search query templates for Envato, Artgrid, and Google Video.

backend/services/cse.go

@@ -64,9 +64,9 @@ func (s *SearchService) SearchMedia(queries []string, enabledPlatforms map[strin
 	results := make([]SearchResult, 0, 90)
 	var lastErr error
 
-	baseQueries := limitQueries(queries, 10)
+	baseQueries := limitQueries(queries, 8)
 	shuffleStrings(baseQueries)
-	primaryQueries := baseQueries[:minInt(len(baseQueries), 5)]
+	primaryQueries := baseQueries[:minInt(len(baseQueries), 4)]
 	runSearchPass := func(bases []string, onlyMissing bool) {
 		for _, base := range bases {
 			base = strings.TrimSpace(base)
@@ -127,7 +127,7 @@ func (s *SearchService) SearchMedia(queries []string, enabledPlatforms map[strin
 }
 
 func (s *SearchService) EnrichResults(results []SearchResult) []SearchResult {
-	limit := minInt(len(results), 18)
+	limit := minInt(len(results), 12)
 	if limit == 0 {
 		return results
 	}

backend/services/ranker.go

@@ -87,7 +87,7 @@ func RankSearchResults(query string, results []SearchResult) []SearchResult {
 }
 
 func GeminiCandidateLimit(total int) int {
-	return total
+	return min(total, 12)
 }
 
 func EvaluateAllCandidatesWithGemini(service *GeminiService, query string, ranked []SearchResult) ([]AIRecommendation, GeminiBatchStats, error) {

backend/services/search_collectors.go

@@ -15,7 +15,7 @@ type searchCollector interface {
 type envatoCollector struct{}
 
 func (envatoCollector) Name() string    { return "Envato" }
-func (envatoCollector) MaxResults() int { return 14 }
+func (envatoCollector) MaxResults() int { return 10 }
 func (envatoCollector) Enabled(enabledPlatforms map[string]bool) bool {
 	return len(enabledPlatforms) == 0 || enabledPlatforms["envato"]
 }
@@ -31,7 +31,7 @@ func (envatoCollector) Enrich(searcher *SearchService, result SearchResult) Sear
 type artgridCollector struct{}
 
 func (artgridCollector) Name() string    { return "Artgrid" }
-func (artgridCollector) MaxResults() int { return 14 }
+func (artgridCollector) MaxResults() int { return 10 }
 func (artgridCollector) Enabled(enabledPlatforms map[string]bool) bool {
 	return len(enabledPlatforms) == 0 || enabledPlatforms["artgrid"]
 }
@@ -47,7 +47,7 @@ func (artgridCollector) Enrich(searcher *SearchService, result SearchResult) Sea
 type googleVideoCollector struct{}
 
 func (googleVideoCollector) Name() string    { return "Google Video" }
-func (googleVideoCollector) MaxResults() int { return 10 }
+func (googleVideoCollector) MaxResults() int { return 8 }
 func (googleVideoCollector) Enabled(enabledPlatforms map[string]bool) bool {
 	return len(enabledPlatforms) == 0 || enabledPlatforms["google video"]
 }