fix(director v2): render tiny-VAE selector as true combo (bare-list spec)

Frontend v1.49.x maps a legacy ("STRING", {"combo": [...]}) tuple to a
free-text widget, not a dropdown. Use the bare-list combo spec shape
(same form as core VAELoader.vae_name) so preview_tiny_vae renders as a
clean model-selector combo; socketless=True in the options dict keeps the
optional input dot hidden.

.tests/test_minimax_h3_director_v2.py

@@ -86,18 +86,21 @@ def test_optional_sampling_sockets_present():
 
 def test_preview_sockets_present():
     opt = MiniMaxH3DirectorV2.INPUT_TYPES()["optional"]
-    # The tiny-VAE selector is a socketless combo widget — rendered like a
+    # The tiny-VAE selector is a bare-list COMBO spec (the same shape as
+    # core VAELoader.vae_name) with socketless=True — rendered like a
     # model selector (e.g. the VAE loader's dropdown), no linkable input
-    # dot on the node edge.
-    assert opt["preview_tiny_vae"][0] == "STRING"
+    # dot on the node edge. In frontend v1.49.x the bare-list form is
+    # what maps to a combo widget; a legacy ("STRING", {"combo": ...})
+    # tuple degrades to a free-text field instead.
+    assert isinstance(opt["preview_tiny_vae"][0], list)
     assert opt["preview_tiny_vae"][1].get("forceInput") is not True
     assert opt["preview_tiny_vae"][1].get("socketless") is True
+    assert opt["preview_tiny_vae"][1].get("default") == "none"
     # The full-quality VAE path remains an optional input socket.
     assert opt["preview_vae"][0] == "VAE"
-    # INPUT_TYPES() is evaluated once at node load: the combo value is the
-    # option list itself, not a callable (callables only appear in specs).
-    combo = opt["preview_tiny_vae"][1].get("combo")
-    names = combo() if callable(combo) else list(combo)
+    # INPUT_TYPES() is evaluated once at node load: the options are the
+    # list itself (element 0 of the tuple), not a callable or a dict key.
+    names = list(opt["preview_tiny_vae"][0])
     assert "none" in names
     if HAS_FOLDER_PATHS:
         # Options come from the models/vae_approx folder listing.

docs/minimax_h3_director.md

@@ -383,7 +383,7 @@ The Director decodes per-step denoising frames itself and streams them into its
 
 - **Toggle:** **live step preview** in the ☰ *Preview & Output options* menu (default on). When off the backend skips the whole decode path (no tiny-VAE decode, no `send_sync`) — a true bypass, not just a hidden pane.
 - **Limits:** `preview_max_resolution` (default 1024 px, 0 = full), `preview_frames` (1 = still JPEG; >1 = animated WebP, or NVENC H.264 MP4 when PyAV probes NVENC), `preview_fps` (default 12).
-- **Decoder precedence:** `preview_tiny_vae` socketless combo widget (a `models/vae_approx` filename selector, e.g. `taeh3.safetensors` — the special H3 tiny decoder that core's `VAELoader` cannot build; rendered like a model selector, no input socket) > `preview_vae` input socket (full-quality `vae.decode()`) > core latent previewer > latent-to-RGB fallback. The tiny-VAE path clamps output before uint8 because taeh3 output is not [0,1]-guaranteed.
+- **Decoder precedence:** `preview_tiny_vae` socketless combo widget (a `models/vae_approx` filename selector, e.g. `taeh3.safetensors` — the special H3 tiny decoder that core's `VAELoader` cannot build; rendered like a model selector, no input socket) > `preview_vae` input socket (full-quality `vae.decode()`) > core latent previewer > latent-to-RGB fallback. The tiny-VAE path clamps output before uint8 because taeh3 output is not [0,1]-guaranteed. Implementation note: the widget must stay a **bare-list combo spec** — `(_vae_approx_options(), {"default": "none", "socketless": True, ...})`, the same shape as core `VAELoader.vae_name`. The legacy `("STRING", {"combo": [...]})` tuple renders as a free-text field (no dropdown) in frontend v1.49.x; `socketless: True` in the options dict is what hides the optional input dot.
 - **KJ alternative:** a KJ `ModelPreviewOverrideKJ` in the chain remains a valid external preview. Because KJ's preview is a native `OUTER_SAMPLE` model wrapper — not a DOM hook on the graph sampler — its own widget also animates during the Director's internal-execution runs. Canonical wiring is unchanged: `Settings.MODEL → KJ.model → KJ.MODEL → Director.ref2va_model`.
 
 ## Dense prompting guide

nodes/nodes_minimax_h3_director_v2.py

@@ -95,7 +95,7 @@ class MiniMaxH3DirectorV2:
                 "external_steps": ("INT", {"default": 0, "min": 0, "forceInput": True}),
                 "external_shift_video": ("FLOAT", {"default": 0.0, "min": 0.0, "forceInput": True}),
                 "external_shift_audio": ("FLOAT", {"default": 0.0, "min": 0.0, "forceInput": True}),
-                "preview_tiny_vae": ("STRING", {"default": "none", "combo": _vae_approx_options(), "socketless": True, "tooltip": "Optional tiny VAE decoder (models/vae_approx) for fast step previews. Overrides preview_vae and the built-in previewer."}),
+                "preview_tiny_vae": (_vae_approx_options(), {"default": "none", "socketless": True, "tooltip": "Optional tiny VAE decoder (models/vae_approx) for fast step previews. Overrides preview_vae and the built-in previewer."}),
                 "preview_vae": ("VAE", {"lazy": True}),
             },
             "hidden": {"prompt_context": "PROMPT", "extra_pnginfo": "EXTRA_PNGINFO", "unique_id": "UNIQUE_ID"},