verify(client): conflict-free desktop AI stream manifest

[HandSonic]

Summary

• verify the independently approved desktop AI SSE failure fix at amended head 39414559884baf72f6be7419f86db6213b5d3251
• remove only the redundant prebuild:web:community SSE insertion while retaining the expanded test:sse-request command
• prove the manifest can merge with selector head 2828cf80e without conflict markers

This is a temporary fork verification PR for the conflict-free manifest amendment associated with upstream OtterMind#2821. It intentionally does not update fix/desktop-ai-chat-error-callback.

Verification

• yarn test:sse-request: passed
• targeted ESLint: passed
• full Community Umi/Webpack build: passed
• postbuild and standalone production bundle verifier: passed
• git diff --check: passed
• merge-tree with selector head 2828cf80e: zero conflict markers and both test scripts retained

Risk

No production logic changed from the reviewed fix. The amendment only removes redundant prebuild invocation; the existing Community CI workflow directly runs yarn test:sse-request.

[HandSonic]

Verification complete. Exact commit 3941455 has been promoted to fork PR #82 and upstream OtterMind#2821. Upstream Frontend, Backend, JavaScript CodeQL, Java CodeQL, dependency review, license, SBOM, and repository checks are all green. Closing this temporary verification PR; the verification branch is intentionally retained.