fix(sagemaker): Use SpaceSettingsSummary.AppType instead of App.AppType (#8276)

## Problem

- Fixes crash when connecting to spaces that have been stopped for long

- The code was incorrectly accessing node.spaceApp.App.AppType, but the
App object is undefined for spaces stopped for long as it deletes the
App resource . This caused below error
```
Error running command aws.smus.openRemoteConnection: Remote connection failed: Cannot read properties of undefined (reading 'AppType'). This is likely caused by the extension that contributes aws.smus.openRemoteConnection.
```


## Solution
Changed to use node.spaceApp.SpaceSettingsSummary.AppType instead, which
-
- Is always available (part of space configuration, not runtime state)
- Contains the correct AppType value needed for start/stop operations
- SpaceSettingsSummary comes from ListSpaces API call and it will always
returns SpaceSettingsSummary as part of the SpaceDetails.
- AppType is a required field in SpaceSettingsSummary because every
SageMaker space must have an application type (JupyterLab or
CodeEditor).
---

- Treat all work as PUBLIC. Private `feature/x` branches will not be
squash-merged at release time.
- Your code changes must meet the guidelines in
[CONTRIBUTING.md](https://github.com/aws/aws-toolkit-vscode/blob/master/CONTRIBUTING.md#guidelines).
- License: I confirm that my contribution is made under the terms of the
Apache 2.0 license.

Author: bhavya2109sharma

packages/core/src/awsService/sagemaker/commands.ts

@@ -171,7 +171,7 @@ export async function stopSpace(
         await client.deleteApp({
             DomainId: node.spaceApp.DomainId!,
             SpaceName: spaceName,
-            AppType: node.spaceApp.App!.AppType!,
+            AppType: node.spaceApp.SpaceSettingsSummary!.AppType!,
             AppName: node.spaceApp.App?.AppName,
         })
     } catch (err) {
@@ -319,7 +319,7 @@ async function handleRunningSpaceWithDisabledAccess(
                 await client.deleteApp({
                     DomainId: node.spaceApp.DomainId!,
                     SpaceName: spaceName,
-                    AppType: node.spaceApp.App!.AppType!,
+                    AppType: node.spaceApp.SpaceSettingsSummary!.AppType!,
                     AppName: node.spaceApp.App?.AppName,
                 })
 
@@ -329,7 +329,11 @@ async function handleRunningSpaceWithDisabledAccess(
                 // Start the space with remote access enabled (skip prompts since user already consented)
                 await client.startSpace(spaceName, node.spaceApp.DomainId!, true)
                 await tryRefreshNode(node)
-                await client.waitForAppInService(node.spaceApp.DomainId!, spaceName, node.spaceApp.App!.AppType!)
+                await client.waitForAppInService(
+                    node.spaceApp.DomainId!,
+                    spaceName,
+                    node.spaceApp.SpaceSettingsSummary!.AppType!
+                )
                 await tryRemoteConnection(node, ctx, progress)
             } catch (err: any) {
                 // Handle user declining instance type upgrade
@@ -369,7 +373,11 @@ async function handleStoppedSpace(
             },
             async (progress) => {
                 progress.report({ message: 'Starting the space' })
-                await client.waitForAppInService(node.spaceApp.DomainId!, spaceName, node.spaceApp.App!.AppType!)
+                await client.waitForAppInService(
+                    node.spaceApp.DomainId!,
+                    spaceName,
+                    node.spaceApp.SpaceSettingsSummary!.AppType!
+                )
                 await tryRemoteConnection(node, ctx, progress)
             }
         )

packages/core/src/test/awsService/sagemaker/commands.test.ts

@@ -59,6 +59,7 @@ describe('SageMaker Commands', () => {
                         AppName: 'default',
                     },
                     SpaceSettingsSummary: {
+                        AppType: 'JupyterLab',
                         RemoteAccess: 'DISABLED',
                     },
                 },