QVAC-24079 fix: raise inactivity timeout in audio-decoder long-WAV test to stop CI flake

[Victor-Rodzko]

🎯 What problem does this PR solve?

• @qvac/inference's test:bare suite intermittently fails "SDK Pod Checks" CI with Error: Audio decoding produced no output for 100ms, reported flaky by @opanin.
• The failure could not be reliably reproduced on demand (rare CI-timing flake).

📝 How does it solve it?

• Root cause: the affected test decodes a real 5-minute WAV through the real @qvac/decoder-audio FFmpegDecoder with inactivityTimeoutMs: 100. That decoder buffers the entire input file (async read) before decoding it in one uninterrupted synchronous burst — every output chunk lands in the same JS tick, so there's no real gap between chunks once decoding starts.
• The only window where the inactivity timer can actually fire is during the initial async file-read/buffering phase, before decoding begins. On a loaded/shared CI runner that read can occasionally exceed 100ms, tripping the timeout — unrelated to the audio's length.
• Fix: raise inactivityTimeoutMs for this one test to 5000ms, giving headroom for CI I/O jitter while staying far below the old fixed 10s total-decode cap the test was written to validate against. The other three tests in the file use a fully mocked decoder response and were never at risk.

🧪 How was it tested?

• Ran the fixed test 10x locally: 10/10 pass.
• Full npm run test for @qvac/inference: 1430/1430 tests pass.
• Reviewed the last ~16 "PR Checks (SDK Pod)" CI runs that executed [inference] test:bare: all passed (flake is rare; confirmed root cause via temporary local timing instrumentation instead, since removed).
• Confirmed on this PR's own CI: [inference] test:bare passed in both "SDK Pod Checks" runs, with the previously-flaky test itself completing in 593ms (well under the new 5000ms window):

  ok - a long WAV decodes fully with an inactivity window far below its total decode time # time = 593ms
  

[github-actions]

Review Status

Current Status: ✅ APPROVED
Approvals so far: Team Lead: 1, Member: 1

[github-actions]

License compliance — clean

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• ./.github/actions/release-merge-guard
• ./docs/website
• ./packages/ggml-coload-smoke
• ./packages/fabric/test/integration
• ./packages/inference-addon-cpp/mobile
• ./packages/sdk/e2e
• ./packages/llm-llamacpp/benchmarks/performance
• ./packages/llm-llamacpp/benchmarks/server
• ./packages/vla-ggml/sim/server
• ./packages/embed-llamacpp/benchmarks/performance
• ./packages/embed-llamacpp/benchmarks/server
• ./packages/asr-ggml/benchmarks/server