Create odsp-client-specific fluidcontainer interface

[znewton]

Description

#25597 includes several changes that require exposing a slightly different, ODSPClient-specific IFluidContainer that exposes container methods like serialize and uploadBlob. Additionally, ODSPClient already returns a customized version of FluidContainer with an overwritten attach method, but the param types are not represented in the standard IFluidContainer type.

Breaking Changes

None. The types introduced here are accurate to the existing types returned by OdspClient, but now they are explicitly specified.

Reviewer Guidance

For examples of how this interface will be extended, see #25597.

[Copilot]

Pull Request Overview

This PR introduces a new IOdspFluidContainer interface that extends the standard IFluidContainer to accommodate ODSP-specific behavior. The main purpose is to properly type the attach method override that already exists in OdspClient, which uses OdspContainerAttachProps instead of the standard ContainerAttachProps.

Key changes:

• Creates IOdspFluidContainer interface extending IFluidContainer with an overridden attach method signature
• Updates return types in OdspClient methods from IFluidContainer to IOdspFluidContainer
• Removes type casting by properly typing the generic parameters

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
packages/service-clients/odsp-client/src/interfaces.ts	Adds new IOdspFluidContainer interface with ODSP-specific attach method signature
packages/service-clients/odsp-client/src/odspClient.ts	Updates return types to use IOdspFluidContainer and adds generic type parameters to eliminate type casts

[github-actions]

🔗 Found some broken links! 💔

Run a link check locally to find them. See
https://github.com/microsoft/FluidFramework/wiki/Checking-for-broken-links-in-the-documentation for more information.

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

 ELIFECYCLE  Command failed with exit code 1.