fix(cursor): support ACP parameterized model picker (#969)

* test: reproduce issue #968

* fix: support Cursor parameterized model picker (closes #968)

cli/src/cursor/utils/cursorAcpModelsSnapshot.ts

@@ -6,6 +6,18 @@ export type CursorModelsSnapshot = {
     currentModelId: string | null;
 };
 
+type CursorAcpModelSnapshotBackend = Pick<AcpSdkBackend, 'getSessionModelsMetadata' | 'getConfigOptionByCategory'>
+    & Partial<Pick<AcpSdkBackend, 'getSessionConfigOptions'>>;
+
+function findConfigOption(
+    backend: CursorAcpModelSnapshotBackend,
+    sessionId: string,
+    key: string
+) {
+    return backend.getConfigOptionByCategory?.(sessionId, key)
+        ?? backend.getSessionConfigOptions?.(sessionId)?.find((option) => option.id === key || option.category === key);
+}
+
 function mergeModelEntries(
     target: Map<string, CursorModelSummary>,
     entries: Iterable<{ modelId: string; name?: string | null }>
@@ -31,19 +43,43 @@ function mergeModelEntries(
  * `availableModels` alone is often one variant per base family.
  */
 export function buildCursorModelsSnapshotFromAcp(
-    backend: Pick<AcpSdkBackend, 'getSessionModelsMetadata' | 'getConfigOptionByCategory'>,
+    backend: CursorAcpModelSnapshotBackend,
     sessionId: string
 ): CursorModelsSnapshot | null {
     const metadata = backend.getSessionModelsMetadata(sessionId);
-    const modelOption = backend.getConfigOptionByCategory?.(sessionId, 'model');
+    const modelOption = findConfigOption(backend, sessionId, 'model');
+    const fastOption = findConfigOption(backend, sessionId, 'fast');
 
     if (!metadata && !modelOption) {
         return null;
     }
 
     const merged = new Map<string, CursorModelSummary>();
+    const parameterizedFastModels: CursorModelSummary[] = [];
 
-    if (modelOption?.options?.length) {
+    if (modelOption?.options?.length && fastOption?.options?.length) {
+        const fastValues = fastOption.options
+            .map((option) => option.value.trim())
+            .filter((value) => value === 'false' || value === 'true');
+        if (fastValues.length > 0) {
+            for (const option of modelOption.options) {
+                const modelId = option.value.trim();
+                if (!modelId || modelId.includes('[')) {
+                    continue;
+                }
+                for (const fast of fastValues) {
+                    parameterizedFastModels.push({
+                        modelId: `${modelId}[fast=${fast}]`,
+                        name: option.name
+                    });
+                }
+            }
+        }
+    }
+
+    if (parameterizedFastModels.length > 0) {
+        mergeModelEntries(merged, parameterizedFastModels);
+    } else if (modelOption?.options?.length) {
         mergeModelEntries(merged, modelOption.options.map((option) => ({
             modelId: option.value,
             name: option.name
@@ -51,16 +87,23 @@ export function buildCursorModelsSnapshotFromAcp(
     }
 
     if (metadata?.availableModels?.length) {
-        mergeModelEntries(merged, metadata.availableModels);
+        mergeModelEntries(
+            merged,
+            parameterizedFastModels.length > 0
+                ? metadata.availableModels.filter((entry) => entry.modelId.includes('['))
+                : metadata.availableModels
+        );
     }
 
     if (merged.size === 0) {
         return null;
     }
 
-    const currentModelId = metadata?.currentModelId
-        ?? modelOption?.currentValue
-        ?? null;
+    const currentModelId = parameterizedFastModels.length > 0 && modelOption?.currentValue && fastOption?.currentValue
+        ? `${modelOption.currentValue}[fast=${fastOption.currentValue}]`
+        : metadata?.currentModelId
+            ?? modelOption?.currentValue
+            ?? null;
 
     return {
         availableModels: [...merged.values()],