Fix Atomic output publishing truncated reports when serialization fails mid-stream

[jzho987]

Station report JSONs sometimes arrive truncated (typically the large base64-inlined WAV reports) and get quarantined as corrupt by the shipper. Root cause: Atomic publishes its temp file in a finally, so any mid-stream failure (lazy attachment read, ENOSPC) still moves partial output into the reports directory under a valid report name — and the test still reports PASS. The temp file also lived in /tmp (cross-filesystem move = non-atomic copy, racing the shipper's 5s poll) and was never fsynced (power yank can leave an empty file after the rename).

• Discard the temp file on failure instead of publishing it
• Create the temp file next to the destination so publishing is a true atomic rename
• fsync before renaming

close() keeps its name and semantics, so hardware-test-framework's AtomicWithPermissions subclass is unaffected. Regression tests included; full suite passes (511 passed, 2 xfailed).

🤖 Generated with Claude Code

[coveralls]

Coverage Report for CI Build 28994926882

Coverage increased (+1.4%) to 62.04%

Details

• Coverage increased (+1.4%) from the base build.
• Patch coverage: 10 of 10 lines across 1 file are fully covered (100%).
• 246 coverage regressions across 9 files.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

246 previously-covered lines in 9 files lost coverage.

File	Lines Losing Coverage	Coverage
openhtf/output/servers/station_server.py	150	0.0%
openhtf/core/test_state.py	35	90.3%
openhtf/core/test_descriptor.py	31	84.91%
openhtf/core/test_executor.py	9	97.09%
openhtf/core/phase_descriptor.py	6	91.6%
openhtf/plugs/init.py	6	95.2%
openhtf/core/test_record.py	4	98.12%
openhtf/output/servers/pub_sub.py	3	0.0%
openhtf/init.py	2	96.83%

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Coverage Stats

Relevant Lines:	7471
Covered Lines:	4635
Line Coverage:	62.04%
Coverage Strength:	3.1 hits per line

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💛 - Coveralls