(gen2-migration) `extractCategory()` uses fragile substring matching that can misclassify resources

### How did you install the Amplify CLI?

_No response_

### If applicable, what version of Node.js are you using?

_No response_

### Amplify CLI Version

0.4.0

### What operating system are you using?

Mac

### Did you make any manual changes to the cloud resources managed by Amplify? Please describe the changes made.

No

### Describe the bug

`extractCategory()` in amplify-cli/src/commands/gen2-migration/categories.ts uses `.includes()` to determine the Amplify category from a CloudFormation logical resource ID. This is order-dependent and prone to false matches. Misclassification could cause resources to be displayed under the wrong category in the user-facing table.

For ex., a storage resource named `"authbackup"` has logical ID `"storageauthbackup"`. `extractCategory("storageauthbackup")` returns `"Auth"` instead of `"Storage"` because `"auth"` is checked first and `"storageauthbackup".includes("auth")` is true.

### Expected behavior

`extractCategory("storageauthbackup")` should return `"Storage"`

### Reproduction steps

1. Create a Gen1 app with `amplify add storage` and name the resource something containing auth
2. Run `amplify push` to deploy
3. Run `amplify gen2-migration decommission`
4. Observe the stateful resources table: the storage resource is listed under Auth instead of Storage

### Project Identifier

_No response_

### Log output

```
# Put your logs below this line

```

### Additional information

_No response_

### Before submitting, please confirm:

- [x] I have done my best to include a minimal, self-contained set of instructions for consistently reproducing the issue.
- [x] I have removed any sensitive information from my code snippets and submission.

Start in amplify-cli/src/commands/gen2-migration/categories.ts and inspect extractCategory(), focusing on how logical resource IDs are matched to categories. Reproduce the reported storageauthbackup case through the gen2-migration decommission flow and verify that the resource appears under Storage rather than Auth.

Written by the indexing model from the issue text.