fix(lambda): match twelve digits in the layer ARN pattern

The account-ID segment was written as `\d{12}` inside a template literal, so the
emitted regex carried a literal `d{12}` and rejected every real layer ARN. The
existing test only covered an over-long name, which is why it passed.

Escapes the backslash and adds the coverage that would have caught it: a real
layer ARN and a bare layer name are both accepted, and an ARN whose account
segment is not twelve digits is rejected.

Author: waleedlatif1

apps/sim/lib/api/contracts/tools/aws/lambda-get-layer-version.ts

@@ -17,7 +17,7 @@ const GetLayerVersionSchema = z.object({
     .min(1, 'layerName is required')
     .max(140, 'layerName cannot exceed 140 characters')
     .regex(
-      /^(arn:[a-zA-Z0-9-]+:lambda:[a-zA-Z0-9-]+:d{12}:layer:[a-zA-Z0-9-_]+)$|^[a-zA-Z0-9-_]+$/,
+      /^(arn:[a-zA-Z0-9-]+:lambda:[a-zA-Z0-9-]+:\d{12}:layer:[a-zA-Z0-9-_]+)$|^[a-zA-Z0-9-_]+$/,
       'layerName must be a layer name or a layer ARN'
     ),
   versionNumber: z.number().int().min(1, 'versionNumber must be at least 1'),

apps/sim/lib/api/contracts/tools/aws/lambda-list-layer-versions.ts

@@ -19,7 +19,7 @@ const ListLayerVersionsSchema = z.object({
     .min(1, 'layerName is required')
     .max(140, 'layerName cannot exceed 140 characters')
     .regex(
-      /^(arn:[a-zA-Z0-9-]+:lambda:[a-zA-Z0-9-]+:d{12}:layer:[a-zA-Z0-9-_]+)$|^[a-zA-Z0-9-_]+$/,
+      /^(arn:[a-zA-Z0-9-]+:lambda:[a-zA-Z0-9-]+:\d{12}:layer:[a-zA-Z0-9-_]+)$|^[a-zA-Z0-9-_]+$/,
       'layerName must be a layer name or a layer ARN'
     ),
   compatibleRuntime: z.string().optional(),

apps/sim/lib/internal/lambda/execute-tool.test.ts

@@ -605,6 +605,42 @@ describe('executeLambdaTool', () => {
     expect(long.status).toBe(400)
   })
 
+  it('accepts a layer ARN as well as a bare layer name', async () => {
+    mockOperations.executeLambdaListLayerVersions.mockResolvedValue({ success: true, output: {} })
+    mockOperations.executeLambdaGetLayerVersion.mockResolvedValue({ success: true, output: {} })
+
+    const arn = await executeLambdaTool(
+      createRequest({
+        toolId: 'lambda_list_layer_versions',
+        input: {
+          ...CONNECTION,
+          layerName: 'arn:aws:lambda:us-east-1:123456789012:layer:my-layer',
+        },
+      })
+    )
+    const bare = await executeLambdaTool(
+      createRequest({
+        toolId: 'lambda_get_layer_version',
+        input: { ...CONNECTION, layerName: 'my-layer', versionNumber: 1 },
+      })
+    )
+
+    expect(arn.status).toBe(200)
+    expect(bare.status).toBe(200)
+  })
+
+  it('rejects a layer ARN whose account segment is not twelve digits', async () => {
+    const response = await executeLambdaTool(
+      createRequest({
+        toolId: 'lambda_list_layer_versions',
+        input: { ...CONNECTION, layerName: 'arn:aws:lambda:us-east-1:notanaccount:layer:my-layer' },
+      })
+    )
+
+    expect(response.status).toBe(400)
+    expect(mockOperations.executeLambdaListLayerVersions).not.toHaveBeenCalled()
+  })
+
   it('rejects a layer name longer than the documented maximum', async () => {
     const response = await executeLambdaTool(
       createRequest({