Keep Wan 2.1-1.3B selectable in small lane (prefer='wan21_t2v_1_3b')

spi/renderers/registry.py

@@ -17,20 +17,26 @@ DEFAULT_REGISTRIES: dict[str, dict[str, Renderer]] = {
         "audio": MockAudioRenderer(),
     },
     "small": {
-        # real backends (Phase 2). The router picks the cheapest capable one: CogVideoX-2b
-        # (fp16, ~5.3 GB VRAM, 6 steps) beats Wan 2.1 T2V-1.3B (bf16, ~8.2 GB) for drafts.
+        # real backends (Phase 2). Cheap-first route picks CogVideoX-2b (fp16, ~5.3 GB,
+        # 6 steps); Wan 2.1 T2V-1.3B (bf16, ~8.2 GB, ~29 GB download incl. fp32 UMT5-XXL)
+        # stays selectable via prefer="wan21_t2v_1_3b".
         "video": CogVideoRenderer("THUDM/CogVideoX-2b"),
         "image": MockImageRenderer(),
         "audio": MockAudioRenderer(),
     },
     "production": {
-        # placeholder quality lane: loads on first use, needs ~80 GB VRAM (Phase 10 hardware)
+        # Phase 10 quality lane placeholder: loads on first use, needs ~80 GB VRAM
         "video": WanRenderer("Wan-AI/Wan2.2-T2V-A14B-Diffusers"),
         "image": MockImageRenderer(),
         "audio": MockAudioRenderer(),
     },
 }
 
+# adapters built + tested in Phase 2 that are not the default route in any lane
+ADDITIONAL_SMALL_RENDERERS = {
+    "wan21_t2v_1_3b": WanRenderer("Wan-AI/Wan2.1-T2V-1.3B-Diffusers"),
+}
+
 
 class ModelRouter:
     def __init__(self, mode: str = "mock") -> None:
@@ -41,6 +47,9 @@ class ModelRouter:
             kind: {renderer.name: renderer}
             for kind, renderer in DEFAULT_REGISTRIES[mode].items()
         }
+        if mode == "small":  # tested Phase 2 adapters remain reachable via prefer=
+            for name, renderer in ADDITIONAL_SMALL_RENDERERS.items():
+                self.register("video", renderer)
 
     def register(self, kind: str, renderer: Renderer) -> None:
         self._lanes.setdefault(kind, {})[renderer.name] = renderer