fix: correct per-model video API field names and remove non-existent models

Each video model uses a different image input field:
- kling-o1-pro/std: first_frame (not image)
- kling-elements-pro/std: images (array)
- minimax-hailuo: image, duration fixed at "6"

Also:
- kling-elements requires slug aspect ratios (square_1_1, etc.)
- Remove wan-2.5 and runway-gen4 which return 404

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

freepik_cli/api/videos.py

@@ -8,10 +8,13 @@ from freepik_cli.api.client import FreepikClient
 from freepik_cli.api.models import (
     VIDEO_POST_ENDPOINTS,
     VIDEO_STATUS_ENDPOINTS,
+    VIDEO_IMAGE_FIELDS,
+    VIDEO_SLUG_ASPECT_RATIO_MODELS,
     VideoModel,
     get_output_urls,
     get_status,
     get_task_id,
+    normalize_aspect_ratio_video,
 )
 
 
@@ -29,15 +32,26 @@ class VideoAPI:
         seed: Optional[int] = None,
     ) -> str:
         """Submit an image-to-video task. Returns task_id."""
-        payload: dict[str, Any] = {
-            "image": image_b64,
-        }
+        image_field = VIDEO_IMAGE_FIELDS[model]
+
+        # kling-elements uses an array; all others use a scalar
+        if image_field == "images":
+            payload: dict[str, Any] = {"images": [image_b64]}
+        else:
+            payload = {image_field: image_b64}
+
         if prompt:
             payload["prompt"] = prompt
-        if duration:
-            payload["duration"] = str(duration)
+
+        # minimax only supports duration=6; clamp silently
+        effective_duration = duration
+        if model == VideoModel.MINIMAX_HAILUO:
+            effective_duration = 6
+        payload["duration"] = str(effective_duration)
+
         if aspect_ratio:
-            payload["aspect_ratio"] = aspect_ratio
+            payload["aspect_ratio"] = normalize_aspect_ratio_video(aspect_ratio, model)
+
         if seed is not None:
             payload["seed"] = seed