(tree) Add summary format version 3 for Edit Manager and Detached Field Index

[agarwal-navin]

This change adds a new breaking summary format (v3) for Edit Manager and Detached Field Index summaries.

#25876 added versioning for shared tree summaries. With that change, future changes to the summary tree structure (with a new version) will make clients fail fast when they do not know that version.
However, clients older than the FF version where versioning was added (2.74) will not fail fast and will likely fail at a random place when trying to read the data. This does not give a good experience to users of FF and also makes debugging harder. So, in this PR, an explicit version is added for Edit Manager and Detached Field Index summaries which changes the location of the summary content. Clients older than 2.74 will fail fast with v3 because they will not find the summary content.

Note: v3 has been added for Forest Summarizer in #26002. That leaves Schema summarizer - the logic to store its content in a different location is not straightforward because it uses incremental summaries and additional handling needs to be done. It will be done separately.

AB#53973

[Copilot]

Pull request overview

This PR adds a new breaking summary format (v3) for Edit Manager and Detached Field Index to ensure older clients (pre-2.74) fail fast when encountering the new format. The v3 format changes the storage location of summary content from legacy keys ("String" and "DetachedFieldIndexBlob") to a standardized "contents" key.

Key changes:

• Introduces v3 summary format versions that change blob key storage locations for better fail-fast behavior
• Adds version-specific files to separate legacy (v1-v2) and new (v3) blob key constants
• Updates summarizers to select appropriate blob keys based on minVersionForCollab configuration
• Sets FluidClientVersion.v2_81 as the threshold for writing v3 format

Reviewed changes

Copilot reviewed 9 out of 10 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
editManagerSummaryFormatV3.ts	Defines new "contents" blob key for EditManager v3 format
editManagerSummaryFormatV1toV2.ts	Extracts legacy "String" blob key used in v1 and v2 formats
detachedFieldIndexSummaryFormatV3.ts	Defines new "contents" blob key for DetachedFieldIndex v3 format
detachedFieldIndexSummaryFormatV1ToV2.ts	Extracts legacy "DetachedFieldIndexBlob" key used in v1 and v2 formats
editManagerSummarizer.ts	Implements v3 format support with version-based blob key selection and backward compatibility
detachedFieldIndexSummarizer.ts	Implements v3 format support with version-based blob key selection and backward compatibility
codec.ts	Adds FluidClientVersion.v2_81 constant and documents v3 format introduction
detachedFieldIndexSummarizer.spec.ts	Updates test to use version-specific import for legacy blob key
summaryFormatV3.ts	Fixes spacing in comment (removes extra space)
tree.alpha.api.md	Updates API surface to include new v2_81 version constant

[github-actions]

🔗 No broken links found! ✅

Your attention to detail is admirable.

linkcheck output

> [email protected] 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"


> [email protected] serve
> docusaurus serve --no-open

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

> [email protected] check-links
> linkcheck http://localhost:3000 --skip-file skipped-urls.txt

Crawling...

Stats:
  248785 links
    1796 destination URLs
    2036 URLs ignored
       0 warnings
       0 errors