fix(api): 补全模型能力继承与响应推导

- 合并 base model 默认能力与平台覆盖项
- 在模型响应中补齐 text_generate 的上下文与推理能力字段
- 为相关逻辑补充测试和迁移脚本

apps/api/internal/store/platform_models_test.go

@@ -0,0 +1,79 @@
+package store
+
+import (
+	"slices"
+	"testing"
+)
+
+func TestEffectivePlatformModelCapabilitiesDeepMergesNestedObjects(t *testing.T) {
+	baseLevels := []any{"none", "minimal", "low"}
+	baseTextGenerate := map[string]any{
+		"max_context_tokens":   204800,
+		"supportThinking":      true,
+		"thinkingEffortLevels": baseLevels,
+	}
+	overrideTextGenerate := map[string]any{
+		"max_thinking_tokens":       131072,
+		"supportThinking":           false,
+		"supportThinkingModeSwitch": true,
+	}
+
+	capabilities := EffectivePlatformModelCapabilities(
+		map[string]any{
+			"originalTypes": []any{"text_generate"},
+			"text_generate": baseTextGenerate,
+		},
+		map[string]any{
+			"text_generate": overrideTextGenerate,
+		},
+	)
+
+	textGenerate, ok := capabilities["text_generate"].(map[string]any)
+	if !ok {
+		t.Fatalf("expected text_generate capabilities object, got %#v", capabilities["text_generate"])
+	}
+	if textGenerate["max_context_tokens"] != 204800 {
+		t.Fatalf("expected base max_context_tokens to be preserved, got %#v", textGenerate["max_context_tokens"])
+	}
+	if textGenerate["max_thinking_tokens"] != 131072 {
+		t.Fatalf("expected override max_thinking_tokens to be applied, got %#v", textGenerate["max_thinking_tokens"])
+	}
+	if textGenerate["supportThinking"] != false {
+		t.Fatalf("expected override supportThinking false to win, got %#v", textGenerate["supportThinking"])
+	}
+	if textGenerate["supportThinkingModeSwitch"] != true {
+		t.Fatalf("expected override supportThinkingModeSwitch true, got %#v", textGenerate["supportThinkingModeSwitch"])
+	}
+	assertAnyStringList(t, textGenerate["thinkingEffortLevels"], []string{"none", "minimal", "low"})
+
+	baseTextGenerate["max_context_tokens"] = 1
+	overrideTextGenerate["max_thinking_tokens"] = 2
+	baseLevels[0] = "changed"
+
+	if textGenerate["max_context_tokens"] != 204800 {
+		t.Fatalf("expected merged capabilities to be detached from base mutations, got %#v", textGenerate["max_context_tokens"])
+	}
+	if textGenerate["max_thinking_tokens"] != 131072 {
+		t.Fatalf("expected merged capabilities to be detached from override mutations, got %#v", textGenerate["max_thinking_tokens"])
+	}
+	assertAnyStringList(t, textGenerate["thinkingEffortLevels"], []string{"none", "minimal", "low"})
+}
+
+func assertAnyStringList(t *testing.T, got any, want []string) {
+	t.Helper()
+	items, ok := got.([]any)
+	if !ok {
+		t.Fatalf("expected string list %v, got %#v", want, got)
+	}
+	normalized := make([]string, 0, len(items))
+	for _, item := range items {
+		text, ok := item.(string)
+		if !ok {
+			t.Fatalf("expected string list %v, got non-string item %#v in %#v", want, item, got)
+		}
+		normalized = append(normalized, text)
+	}
+	if !slices.Equal(normalized, want) {
+		t.Fatalf("expected string list %v, got %v", want, normalized)
+	}
+}