Cherry-pick of the 3 value commits from #11323 (by @RaviTharuma), dropping 17 already-merged rebase-baggage commits. Validated in a combined-batch worktree off release/v3.8.51 tip:
- typecheck:core, file-size, changelog-integrity, complexity, cognitive-complexity gates — all OK
- Focused tests, isolated re-run flake-free: accountSemaphore.test.ts 11/11, chatcore-hierarchical-admission.test.ts 2/2, resilience-settings-provider-quota-overrides.test.ts 12/12, i18n-vi-completeness.test.ts 5/5
- lint clean once isolated from the unrelated ESLint-10 suppressions regression carried by a separate PR in the batch
Closes#7778. Full credit to @RaviTharuma for the design and implementation.
Register AWS Polly as an audio provider with SigV4 request signing,
speech engine discovery, and API-key validation for managed provider
flows.
Add Lemonade as a self-hosted OpenAI-compatible provider, expand
static model discovery to audio registries, and support Azure OpenAI
deployment discovery from resource endpoints.
Sanitize sensitive provider-specific AWS fields in API responses and
update related tests and release notes.
- Stream release: wrap stream body with TransformStream to release
account semaphore only when stream is fully consumed (Thread 1)
- Key scope: remove model from semaphore key — was per-account-per-model,
now truly per-account to match PR motivation (Thread 2)
- Test location: move accountSemaphore.test.ts to tests/unit/ per style guide (Thread 3)
- Fix flaky timestamp assertions in semaphore tests
