fix: add support for ACP writeTextFile clientCapability

[aprogramq]

Issue for this PR

Fixes #4240

Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

What does this PR do?

This fixes ACP file syncing for clients that advertise the fs.writeTextFile capability.
The change stores clientCapabilities during ACP initialization, includes sessionID in file.edited events, and on file edits sends the updated file contents back to the ACP client through writeTextFile.

The SDK/OpenAPI types were updated as part of the event shape change.

How did you verify your code works?

Zed editor

Checklist

• I have tested my changes locally
• I have not included unrelated changes in this PR

I'm reopening this pull request 6902, as it was closed due to the time limit expiring. The issue is still relevant.

[github-actions]

Hey! Your PR title [REOPEN] fix: add support for ACP writeTextFile clientCapability doesn't follow conventional commit format.

Please update it to start with one of:

• feat: or feat(scope): new feature
• fix: or fix(scope): bug fix
• docs: or docs(scope): documentation changes
• chore: or chore(scope): maintenance tasks
• refactor: or refactor(scope): code refactoring
• test: or test(scope): adding or updating tests

Where scope is the package name (e.g., app, desktop, opencode).

See CONTRIBUTING.md for details.

[github-actions]

Thanks for your contribution!

This PR doesn't have a linked issue. All PRs must reference an existing issue.

Please:

1. Open an issue describing the bug/feature (if one doesn't exist)
2. Add Fixes #<number> or Closes #<number> to this PR description

See CONTRIBUTING.md for details.

[github-actions]

Thanks for updating your PR! It now meets our contributing guidelines. 👍