fix aspect ratio matching

crates/api_clients/artcraft/artcraft_router/src/generate/generate_video/plan/fal/plan_generate_video_fal_seedance_1p5_pro.rs

@@ -118,11 +118,27 @@ fn plan_aspect_ratio(
           value: format!("{:?}", unsupported),
         }))
       }
-      _ => Ok(Some(Ar::Auto)),
+      _ => Ok(Some(nearest_aspect_ratio(unsupported))),
     },
   }
 }
 
+/// Pick the nearest supported aspect ratio for unsupported inputs.
+fn nearest_aspect_ratio(aspect_ratio: CommonAspectRatio) -> FalSeedance1p5ProAspectRatio {
+  use FalSeedance1p5ProAspectRatio as Ar;
+  match aspect_ratio {
+    // Wide unsupported → nearest wide
+    CommonAspectRatio::WideFiveByFour => Ar::FourByThree,     // 1.25 → 1.33
+    CommonAspectRatio::WideThreeByTwo => Ar::FourByThree,      // 1.50 → 1.33
+    // Tall unsupported → nearest tall
+    CommonAspectRatio::TallFourByFive => Ar::ThreeByFour,     // 0.80 → 0.75
+    CommonAspectRatio::TallTwoByThree => Ar::ThreeByFour,     // 0.67 → 0.75
+    CommonAspectRatio::TallNineByTwentyOne => Ar::NineBySixteen, // 0.43 → 0.56
+    // Anything else → Square
+    _ => Ar::Square,
+  }
+}
+
 fn plan_resolution(
   resolution: Option<CommonResolution>,
   strategy: RequestMismatchMitigationStrategy,

crates/service/web/storyteller_web/src/http_server/endpoints/omni_gen/generate/video/tests/test_seedance_1p5_pro.rs

@@ -359,26 +359,40 @@ mod tests {
         });
       }
 
-      // ── Unsupported aspect ratios fall back under PayMoreUpgrade ──────────
+      // ── Unsupported aspect ratios fall back to nearest under PayMoreUpgrade
 
       #[test]
-      fn wide_5x4_falls_back_to_auto() {
+      fn wide_5x4_falls_back_to_four_by_three() {
         with_text_plan(&make_request(Some("p"), Some(CommonAspectRatio::WideFiveByFour), None, None, None, None, None), |plan| {
-          assert!(matches!(plan.aspect_ratio, Some(FalSeedance1p5ProAspectRatio::Auto)));
+          assert!(matches!(plan.aspect_ratio, Some(FalSeedance1p5ProAspectRatio::FourByThree)));
         });
       }
 
       #[test]
-      fn wide_3x2_falls_back_to_auto() {
+      fn wide_3x2_falls_back_to_four_by_three() {
         with_text_plan(&make_request(Some("p"), Some(CommonAspectRatio::WideThreeByTwo), None, None, None, None, None), |plan| {
-          assert!(matches!(plan.aspect_ratio, Some(FalSeedance1p5ProAspectRatio::Auto)));
+          assert!(matches!(plan.aspect_ratio, Some(FalSeedance1p5ProAspectRatio::FourByThree)));
         });
       }
 
       #[test]
-      fn tall_4x5_falls_back_to_auto() {
+      fn tall_4x5_falls_back_to_three_by_four() {
         with_text_plan(&make_request(Some("p"), Some(CommonAspectRatio::TallFourByFive), None, None, None, None, None), |plan| {
-          assert!(matches!(plan.aspect_ratio, Some(FalSeedance1p5ProAspectRatio::Auto)));
+          assert!(matches!(plan.aspect_ratio, Some(FalSeedance1p5ProAspectRatio::ThreeByFour)));
+        });
+      }
+
+      #[test]
+      fn tall_2x3_falls_back_to_three_by_four() {
+        with_text_plan(&make_request(Some("p"), Some(CommonAspectRatio::TallTwoByThree), None, None, None, None, None), |plan| {
+          assert!(matches!(plan.aspect_ratio, Some(FalSeedance1p5ProAspectRatio::ThreeByFour)));
+        });
+      }
+
+      #[test]
+      fn tall_9x21_falls_back_to_nine_by_sixteen() {
+        with_text_plan(&make_request(Some("p"), Some(CommonAspectRatio::TallNineByTwentyOne), None, None, None, None, None), |plan| {
+          assert!(matches!(plan.aspect_ratio, Some(FalSeedance1p5ProAspectRatio::NineBySixteen)));
         });
       }