Remove the TaggedLoggerAdapter compatibility fallback

[Mark Fields (markfields)]

Description

Removes the deprecated internal TaggedLoggerAdapter and the container runtime fallback that adapted untagged loggers from loader 0.45-era container contexts.

Supported loaders provide IContainerContext.taggedLogger. The historical fallback is outside the current 12-month Runtime-to-Loader layer compatibility window, and @internal APIs carry no stability guarantee. The layer compatibility and telemetry utilities design documentation now clarify these expectations.

No customer-facing API reports changed, so this does not require a changeset or API Council review.

Validation:

• CI readiness checks passed for @fluidframework/container-runtime and @fluidframework/telemetry-utils
• ESLint passed
• API report and documentation generation passed
• @fluidframework/telemetry-utils: 256 tests passed
• @fluidframework/container-runtime: 975 tests passed, 1 pending

Reviewer Guidance

The review process is outlined on this wiki page.

Please verify that the current layer compatibility window is the correct basis for removing the loader 0.45 fallback.

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• Correctness — logic errors, race conditions, lifecycle issues
• Security — vulnerabilities, secret exposure, injection
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• Performance — algorithmic regressions, memory leaks
• Testing — coverage gaps, hollow tests

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[Copilot]

🟢 Approval recommended

The deprecated adapter and runtime fallback are cleanly removed with corresponding test/doc updates and no remaining in-repo references.

Pull request overview

This PR removes the deprecated internal TaggedLoggerAdapter and the container runtime’s legacy fallback that adapted untagged loggers from older (loader 0.45-era) container contexts, aligning runtime↔loader expectations with the documented rolling layer compatibility windows.

Changes:

• Deleted TaggedLoggerAdapter from @fluidframework/telemetry-utils and removed its internal re-export.
• Removed ContainerRuntime fallback logic that wrapped context.logger when context.taggedLogger was absent, now requiring context.taggedLogger.
• Updated documentation to clarify that tagged logger adaptation is not provided outside the supported layer compatibility window.

File summaries

File	Description
packages/utils/telemetry-utils/src/test/errorLogging.spec.ts	Removes tests that exercised the deleted TaggedLoggerAdapter.
packages/utils/telemetry-utils/src/logger.ts	Deletes the deprecated internal TaggedLoggerAdapter implementation.
packages/utils/telemetry-utils/src/internal.ts	Stops re-exporting TaggedLoggerAdapter via the internal entrypoint.
packages/utils/telemetry-utils/DEV.md	Documents that tagged logger adaptation is not provided outside the layer compatibility window.
packages/runtime/container-runtime/src/containerRuntime.ts	Removes old-loader fallback and uses context.taggedLogger directly.
LayerCompatibility.md	Clarifies that rolling support windows supersede the older fixed-loader-LTS compatibility policy.

Review details

• Files reviewed: 6/6 changed files
• Comments generated: 0
• Review effort level: Lite

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[github-actions]

Fleet Review — Clean

No issues found across the reviewer fleet for this run.

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[github-actions]

🔗 No broken links found! ✅

Your attention to detail is admirable.

linkcheck output

$ start-server-and-test "npm run serve -- --host 127.0.0.1 --no-open" http://127.0.0.1:3000 check-links
1: starting server using command "npm run serve -- --host 127.0.0.1 --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-website@0.0.0 serve
> docusaurus serve --host 127.0.0.1 --no-open

[SUCCESS] Serving "build" directory at: http://127.0.0.1:3000/

> fluid-framework-website@0.0.0 check-links
> linkcheck http://127.0.0.1:3000 --skip-file skipped-urls.txt

Crawling...

Stats:
  340615 links
    2042 destination URLs
    2297 URLs ignored
       0 warnings
       0 errors

[github-actions]

Bundle size comparison

Base commit: f57cde7412798b35161e3c2d068ce35ab26483fd
Head commit: 0d51517c2bdfb81f866ffc3c139ed65b4909eb45

Notable changes

No bundles changed by ≥ 500 bytes parsed.

Per-bundle deltas

@fluid-example/bundle-size-tests

• fluidFrameworkAllAlpha.js: parsed 804388 → 804444 (+56), gzip 221073 → 221132 (+59)
• azureClient.js: parsed 634027 → 633685 (-342), gzip 169868 → 169831 (-37)
• odspClient.js: parsed 605273 → 605047 (-226), gzip 162668 → 162701 (+33)
• aqueduct.js: parsed 537952 → 537626 (-326), gzip 144493 → 144421 (-72)
• fluidFramework.js: parsed 413402 → 413435 (+33), gzip 117287 → 117287 (0)
• sharedTree.js: parsed 402781 → 402807 (+26), gzip 114725 → 114731 (+6)
• containerRuntime.js: parsed 314719 → 314365 (-354), gzip 86326 → 86211 (-115)
• sharedString.js: parsed 175239 → 175246 (+7), gzip 49670 → 49677 (+7)
• experimentalSharedTree.js: parsed 161846 → 161846 (0), gzip 46722 → 46722 (0)
• matrix.js: parsed 159618 → 159625 (+7), gzip 45914 → 45921 (+7)
• loader.js: parsed 147327 → 147343 (+16), gzip 40038 → 40048 (+10)
• odspDriver.js: parsed 105689 → 105747 (+58), gzip 32933 → 33000 (+67)
• directory.js: parsed 65669 → 65676 (+7), gzip 18493 → 18501 (+8)
• 578.js: parsed 58686 → 58686 (0), gzip 17657 → 17657 (0)
• odspPrefetchSnapshot.js: parsed 45921 → 45902 (-19), gzip 15347 → 15357 (+10)
• map.js: parsed 45820 → 45827 (+7), gzip 14119 → 14126 (+7)
• 252.js: parsed 44384 → 44384 (0), gzip 13741 → 13741 (0)
• summarizerDelayLoadedModule.js: parsed 31287 → 31287 (0), gzip 7929 → 7929 (0)
• socketModule.js: parsed 26992 → 26962 (-30), gzip 8019 → 8052 (+33)
• createNewModule.js: parsed 12464 → 12464 (0), gzip 4792 → 4805 (+13)
• summaryModule.js: parsed 3888 → 3888 (0), gzip 1874 → 1874 (0)
• connectionState.js: parsed 909 → 909 (0), gzip 500 → 500 (0)
• sharedTreeAttributes.js: parsed 845 → 852 (+7), gzip 493 → 502 (+9)
• debugAssert.js: parsed 429 → 429 (0), gzip 299 → 299 (0)
• FluidFramework-HashFallback.js: parsed 419 → 419 (0), gzip 313 → 313 (0)