Expand search coverage and preview parsing

backend/services/gemini.go

@@ -71,7 +71,7 @@ func (g *GeminiService) TranslateQuery(query string) string {
 			"systemInstruction": map[string]any{
 				"parts": []map[string]string{
 					{
-						"text": "You translate media search intents into natural English. Output one plain English search phrase only. No labels, no quotes, no explanations.",
+						"text": "You are a professional video editor. Infer stronger stock-footage and scene-search wording from the user's keyword, and expand it into natural English that a professional editor would use to find usable footage. Output one plain English search phrase only. No labels, no quotes, no explanations.",
 					},
 				},
 			},
@@ -79,7 +79,7 @@ func (g *GeminiService) TranslateQuery(query string) string {
 				{
 					"parts": []map[string]string{
 						{
-							"text": "Translate this user query into concise English suitable for stock-footage search: " + trimmed,
+							"text": "Expand this user query into a concise but editor-grade English footage search phrase suitable for stock-footage discovery: " + trimmed,
 						},
 					},
 				},
@@ -152,13 +152,13 @@ func (g *GeminiService) Recommend(query string, candidates []SearchResult) ([]AI
 	type geminiPart map[string]any
 	parts := []geminiPart{
 		{
-			"text": `Analyze the provided images for the user's search intent. Return JSON only in this shape:
+			"text": `You are a professional video editor. Analyze whether each provided visual is suitable as a usable scene or shot for the user's requested keyword. Return JSON only in this shape:
 {"recommendations":[{"index":0,"reason":"short reason","recommended":true}]}
 Return one entry for every analyzed candidate. Use Korean for every reason. Keep reasons concise but specific enough to explain usefulness.
 Mark the strongest matches as recommended=true and weaker matches as recommended=false.
 Prefer cinematic b-roll, stock footage, editorial footage, clean composition, usable establishing shots, and professional media thumbnails.
 Avoid clickbait faces, exaggerated expressions, meme aesthetics, low-information thumbnails, sensational text overlays, or gossip-style imagery.
-Favor thumbnails that look directly useful for media editing and footage sourcing.
+Favor scenes that look directly useful for professional editing, sequencing, establishing, cutaway, or mood-building usage.
 User query: ` + query,
 		},
 	}