feat(logs): add copy-all button to request detail modal [defer to 3.8.51]

[AndrianBalanescu]

Summary

• Adds a Copy all button to the request detail modal header so operators can copy the entire multi-stage transcript (client/provider payloads, stream chunks, or legacy request/response) in one click instead of copying each accordion card manually.
• Extracts buildCopyAllText() as a pure, exported helper in src/shared/components/RequestLoggerDetail.tsx.
• Adds copyAll and copiedAll translation strings across all 43 supported locales.
• Adds comprehensive unit tests for buildCopyAllText() in tests/unit/request-logger-detail-copy-all.test.ts.

Testing

• node --import tsx/esm --test tests/unit/request-logger-detail-copy-all.test.ts passes (4/4).
• ESLint checks clean for changed files.

[diegosouzapw]

Solid little UX win — extracting buildCopyAllText as a pure exported helper was the right call; we ran your 4 tests on the current release/v3.8.51 tip and they pass, and the copy path reuses the modal's existing onCopy so clipboard fallback/XSS concerns are inherited-solved. Before merge: please add a changelog.d/features entry like the other PRs in this cycle — the Merge integrity job is red on the PR and the missing entry is the likely owner. Also note the 43 locale entries carry English 'Copy all'/'Copied all' placeholders; keys are present so the coverage gate is happy, but a translation pass (or the usual sync flow) would be welcome as a follow-up. The live modal click-through (clipboard write in a real browser) hasn't been exercised by us — if you have a screenshot/clip of it working, drop it in the thread.