fix(context): Change snapshotter model config. (#26745)

docs/reference/configuration.md

@@ -700,6 +700,19 @@ their corresponding top-level category object in your `settings.json` file.
         "extends": "gemini-3-flash-base",
         "modelConfig": {}
       },
+      "context-snapshotter": {
+        "extends": "gemini-3-flash-base",
+        "modelConfig": {
+          "generateContentConfig": {
+            "thinkingConfig": {
+              "thinkingLevel": "HIGH"
+            },
+            "temperature": 1,
+            "topP": 0.95,
+            "topK": 64
+          }
+        }
+      },
       "chat-compression-3-pro": {
         "modelConfig": {
           "model": "gemini-3-pro-preview"

packages/core/src/config/defaultModelConfigs.ts

@@ -221,6 +221,19 @@ export const DEFAULT_MODEL_CONFIGS: ModelConfigServiceConfig = {
       extends: 'gemini-3-flash-base',
       modelConfig: {},
     },
+    'context-snapshotter': {
+      extends: 'gemini-3-flash-base',
+      modelConfig: {
+        generateContentConfig: {
+          thinkingConfig: {
+            thinkingLevel: ThinkingLevel.HIGH,
+          },
+          temperature: 1,
+          topP: 0.95,
+          topK: 64,
+        },
+      },
+    },
     'chat-compression-3-pro': {
       modelConfig: {
         model: 'gemini-3-pro-preview',

packages/core/src/context/utils/snapshotGenerator.ts

@@ -207,7 +207,7 @@ ${formatNodesForLlm(nodes)}`;
     try {
       const result = await this.env.llmClient.generateJson({
         role: LlmRole.UTILITY_STATE_SNAPSHOT_PROCESSOR,
-        modelConfigKey: { model: 'gemini-3-flash-base' },
+        modelConfigKey: { model: 'context-snapshotter' },
         contents: [{ role: 'user', parts: [{ text: userPromptText }] }],
         systemInstruction: { role: 'system', parts: [{ text: systemPrompt }] },
         schema: patchSchema,

packages/core/src/services/test-data/resolved-aliases-retry.golden.json

@@ -253,6 +253,17 @@
       "topP": 1
     }
   },
+  "context-snapshotter": {
+    "model": "gemini-3-flash-preview",
+    "generateContentConfig": {
+      "temperature": 1,
+      "topP": 0.95,
+      "thinkingConfig": {
+        "thinkingLevel": "HIGH"
+      },
+      "topK": 64
+    }
+  },
   "chat-compression-3-pro": {
     "model": "gemini-3-pro-preview",
     "generateContentConfig": {}

packages/core/src/services/test-data/resolved-aliases.golden.json

@@ -253,6 +253,17 @@
       "topP": 1
     }
   },
+  "context-snapshotter": {
+    "model": "gemini-3-flash-preview",
+    "generateContentConfig": {
+      "temperature": 1,
+      "topP": 0.95,
+      "thinkingConfig": {
+        "thinkingLevel": "HIGH"
+      },
+      "topK": 64
+    }
+  },
   "chat-compression-3-pro": {
     "model": "gemini-3-pro-preview",
     "generateContentConfig": {}