feat: show generation prompts in previews and fix fluid page layout

tests/test_app.py

@@ -73,6 +73,18 @@ class AppTests(unittest.TestCase):
         self.assertEqual(self.client.delete("/api/galleries/user/" + image["filename"]).status_code, 200)
         self.assertEqual(self.client.get(image["url"]).status_code, 404)
 
+    def test_gallery_prompt_and_legacy_image(self):
+        prompt = "第一行提示词\n<script>保持原样显示</script>"
+        with patch.object(ProviderAdapter, "_request", side_effect=self.upstream):
+            result = self.client.post("/api/generate", json={**self.payload, "prompt": prompt,
+                                                           "profile_name": "prompt-preview"})
+        result.raise_for_status()
+        filename = result.json()["images"][0]["filename"]
+        (config.OUTPUT_DIR / "prompt-preview" / "legacy.png").write_bytes(PNG)
+        items = {item["filename"]: item for item in self.client.get("/api/galleries/prompt-preview").json()}
+        self.assertEqual(items[filename]["prompt"], prompt)
+        self.assertEqual(items["legacy.png"]["prompt"], "")
+
     def test_disabled_or_unknown_model_never_calls_upstream(self):
         for model, enabled, status in (("missing-image", True, 404), ("test-image", False, 400)):
             providers.set_model_enabled("test:test-image", enabled)