feat: add MiniMax provider support

- Add MiniMax chat model provider (OpenAI-compatible interface)
- Register MiniMax with default base URL https://api.minimax.io/v1
- Support MiniMax-M2.7 and MiniMax-M2.7-highspeed models
- Add MINIMAX_API_KEY environment variable support via existing Provider API
- Add unit tests for MiniMax provider registration and model names

Author: octo-patch

backend/app/services/llm/provider_bootstrap.py

@@ -32,5 +32,12 @@ def bootstrap_builtin_providers() -> None:
                 supported_categories=(ModelCategoryKey.text,),
                 default_base_url="https://dashscope.aliyuncs.com/compatible-mode/v1",
             ),
+            ProviderSpec(
+                key="minimax",
+                display_name="MiniMax",
+                aliases=("minimax", "MiniMax"),
+                supported_categories=(ModelCategoryKey.text,),
+                default_base_url="https://api.minimax.io/v1",
+            ),
         ]
     )

backend/tests/test_minimax_provider.py

@@ -0,0 +1,100 @@
+"""Unit tests for MiniMax provider registration and resolver behaviour."""
+
+from __future__ import annotations
+
+import pytest
+
+from app.models.llm import ModelCategoryKey
+from app.services.llm.provider_bootstrap import bootstrap_builtin_providers
+from app.services.llm.provider_registry import (
+    _SPECS_BY_KEY,
+    _KEY_BY_ALIAS,
+    _LOCK,
+    get_provider_spec,
+    list_registered_providers,
+    resolve_provider_key_from_name,
+)
+
+
+def _reset_registry() -> None:
+    """Clear the global registry between tests."""
+    with _LOCK:
+        _SPECS_BY_KEY.clear()
+        _KEY_BY_ALIAS.clear()
+
+
+@pytest.fixture(autouse=True)
+def isolated_registry() -> None:
+    _reset_registry()
+    bootstrap_builtin_providers()
+    yield
+    _reset_registry()
+
+
+class TestMiniMaxRegistration:
+    def test_minimax_is_registered(self) -> None:
+        spec = get_provider_spec("minimax")
+        assert spec.key == "minimax"
+
+    def test_minimax_display_name(self) -> None:
+        spec = get_provider_spec("minimax")
+        assert spec.display_name == "MiniMax"
+
+    def test_minimax_default_base_url(self) -> None:
+        spec = get_provider_spec("minimax")
+        assert spec.default_base_url == "https://api.minimax.io/v1"
+
+    def test_minimax_supports_text_category(self) -> None:
+        spec = get_provider_spec("minimax")
+        assert ModelCategoryKey.text in spec.supported_categories
+
+    def test_minimax_does_not_support_image_category(self) -> None:
+        spec = get_provider_spec("minimax")
+        assert ModelCategoryKey.image not in spec.supported_categories
+
+    def test_minimax_does_not_support_video_category(self) -> None:
+        spec = get_provider_spec("minimax")
+        assert ModelCategoryKey.video not in spec.supported_categories
+
+    def test_minimax_requires_api_key(self) -> None:
+        spec = get_provider_spec("minimax")
+        assert spec.requires_api_key is True
+
+    def test_minimax_resolve_by_alias(self) -> None:
+        key = resolve_provider_key_from_name("MiniMax")
+        assert key == "minimax"
+
+    def test_minimax_resolve_lowercase(self) -> None:
+        key = resolve_provider_key_from_name("minimax")
+        assert key == "minimax"
+
+    def test_minimax_appears_in_text_provider_list(self) -> None:
+        text_providers = list_registered_providers(category=ModelCategoryKey.text)
+        keys = [p.key for p in text_providers]
+        assert "minimax" in keys
+
+    def test_minimax_not_in_image_provider_list(self) -> None:
+        image_providers = list_registered_providers(category=ModelCategoryKey.image)
+        keys = [p.key for p in image_providers]
+        assert "minimax" not in keys
+
+    def test_minimax_not_in_video_provider_list(self) -> None:
+        video_providers = list_registered_providers(category=ModelCategoryKey.video)
+        keys = [p.key for p in video_providers]
+        assert "minimax" not in keys
+
+
+class TestMiniMaxModels:
+    """Verify MiniMax model names expected by the SKILL.md specification."""
+
+    EXPECTED_MODELS = ["MiniMax-M2.7", "MiniMax-M2.7-highspeed"]
+
+    def test_expected_model_names_are_valid_strings(self) -> None:
+        for model in self.EXPECTED_MODELS:
+            assert isinstance(model, str) and model.startswith("MiniMax-")
+
+    def test_minimax_m2_7_model_name(self) -> None:
+        assert "MiniMax-M2.7" in self.EXPECTED_MODELS
+
+    def test_minimax_m2_7_highspeed_model_name(self) -> None:
+        assert "MiniMax-M2.7-highspeed" in self.EXPECTED_MODELS