chore: add SSH key support for CE git connect flow (#41632)

## Description
Adds SSH key management support to the CE git connect flow.

### Changes
- **Client – ConnectInitialize**: Added `formData.sshKeySource` and
`formData.sshKeyId` to the `useEffect` dependency array so the connect
step reacts to SSH key selection changes.
- **Client – connectSaga**: Passed `sshKeyId` through in
`ConnectRequestParams` so it reaches the backend on connect.
- **Server – GitFSServiceCEImpl**: Fixed reactive chain by replacing
`.flatMap` with `.then` on the `deleteLocalRepo` call during error
handling, ensuring correct signal propagation.

Fixes #`Issue Number`  

## Automation

/ok-to-test tags="@tag.Git"

### :mag: Cypress test results
<!-- This is an auto-generated comment: Cypress test results  -->
> [!TIP]
> 🟢 🟢 🟢 All cypress tests have passed! 🎉 🎉 🎉
> Workflow run:
<https://github.com/appsmithorg/appsmith/actions/runs/23242272689>
> Commit: fc48d00fe44b23d54601aae901b24ae3f017f30b
> <a
href="https://internal.appsmith.com/app/cypress-dashboard/rundetails-65890b3c81d7400d08fa9ee5?branch=master&workflowId=23242272689&attempt=3"
target="_blank">Cypress dashboard</a>.
> Tags: `@tag.Git`
> Spec:
> <hr>Wed, 18 Mar 2026 12:38:06 UTC
<!-- end of auto-generated comment: Cypress test results  -->

## Test plan
- [ ] Verify git connect flow works with SSH key selection in CE
- [ ] Verify error handling during connect cleans up local repo
correctly
- [ ] Verify existing git connect flow without SSH key still works


Made with [Cursor](https://cursor.com)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **Bug Fixes**
* SSH key selection now reliably triggers UI updates during Git
initialization when the key source or chosen key changes.
* The selected SSH key identifier is correctly included in Git
connection requests so the intended key is used.
* Remote repository error handling improved so analytics complete
reliably and cleanup proceeds without disrupting subsequent steps.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->