docs(driver): Add deprecation comment and changeset for disconnect event

[RishhiB]

This PR adds a changeset to document an upcoming breaking change to the disconnect event in the driver layer. The reason parameter will become optional to enable better handling of clean, intentional disconnections.

Breaking Changes

disconnect event reason parameter will become optional

To enable better handling of clean, intentional disconnects (e.g. Container.dispose()), the reason parameter of the disconnect event on IDocumentDeltaConnectionEvents is being deprecated as a required parameter.

Current signature:

listener: (reason: IAnyDriverError) => void

Future signature (v2.60):

listener: (reason?: IAnyDriverError) => void

Impact: Developers with listeners for the disconnect event should update their implementations to handle cases where the reason parameter is undefined. This indicates a clean disconnect, which should not be treated as an error.

Timeline: The breaking change is scheduled to be released in version 2.60.

Reviewer Guidance

This is a documentation-only change that adds a changeset to inform users of an upcoming breaking change. The changeset will be processed during the next release to generate appropriate release notes and version bumps for the affected packages:

• @fluidframework/container-loader
• @fluidframework/driver-base
• @fluidframework/driver-definitions

[Copilot]

Pull Request Overview

This PR updates documentation to deprecate the required reason parameter for the disconnect event, indicating that it will become optional in the upcoming v2.60 release.

• Adds a deprecation comment to the disconnect event in the driver definitions.
• Updates the changeset to document the breaking change for affected packages.

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
packages/common/driver-definitions/src/storage.ts	Adds a deprecation comment to the disconnect event listener signature.
.changeset/fuzzy-turkeys-help.md	Provides a changeset detailing the breaking change with the updated event signature.

[github-actions]

🔗 No broken links found! ✅

Your attention to detail is admirable.

linkcheck output

> fluid-framework-docs-site@0.0.0 ci:check-links /home/runner/work/FluidFramework/FluidFramework/docs
> start-server-and-test "npm run serve -- --no-open" 3000 check-links

1: starting server using command "npm run serve -- --no-open"
and when url "[ 'http://127.0.0.1:3000' ]" is responding with HTTP status code 200
running tests using command "npm run check-links"


> fluid-framework-docs-site@0.0.0 serve
> docusaurus serve --no-open

[SUCCESS] Serving "build" directory at: http://localhost:3000/

> fluid-framework-docs-site@0.0.0 check-links
> linkcheck http://localhost:3000 --skip-file skipped-urls.txt

Crawling...

Stats:
  225443 links
    1710 destination URLs
    1941 URLs ignored
       0 warnings
       0 errors

[Josmithr]

Left one more small suggestion. Otherwise, looks good to me!

[jason-ha]

I think some revisions are needed.

[jason-ha]

How did you pick this set? To me it feels either too short or too long. Why container-loader but not others?

[jason-ha]

"deprecated as a required parameter" seems odd for an event. In practice we'll probably always send an argument. It is just that undefined might be the value we send.
Think about it this way. What if there was other information that we wanted to send with this event? What if we always wanted to send some other argument that follows reason? What would the signature look like? Internally how would we pass the second parameter without the first? (Hint: it can't be done in current versions of TypeScript.)
So optional is not the right signature for an event.

[RishhiB]

changing this to required but allowed to be undefined

[jason-ha]

How does this doc work? reason is not a parameter of (event: "disconnect", listener: ...)?

[jason-ha]

text files should always have an empty blank line at the end