fix(fuzz): VortexError in file_io (#8249)

[vortex-claude]

Automated draft fix for fuzzer issue #8249.

• Target: file_io
• Crash file: crash-10053bb7dbb3978fcb50a22c8acba85b774226a9

Claude reproduced the crash, applied a minimal fix, and added a regression
test. The full analysis, diff, and test output are posted on issue
#8249.

This is a draft: please review carefully before marking it ready. The
linked issue is closed automatically by the nightly retest workflow once
the crash no longer reproduces, so this PR does not close it on merge.

View Claude run

[codspeed-hq]

Merging this PR will not alter performance

⚠️ Unknown Walltime execution environment detected

Using the Walltime instrument on standard Hosted Runners will lead to inconsistent data.

For the most accurate results, we recommend using CodSpeed Macro Runners: bare-metal machines fine-tuned for performance measurement consistency.

⚡ 118 improved benchmarks
❌ 54 regressed benchmarks
✅ 1341 untouched benchmarks

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	Simulation	compare[63]	244.6 µs	360.7 µs	-32.18%
❌	Simulation	compare[56]	229.5 µs	332.4 µs	-30.97%
❌	Simulation	compare[62]	254.7 µs	368.9 µs	-30.96%
❌	Simulation	compare[60]	248.3 µs	358.7 µs	-30.76%
❌	Simulation	compare[61]	255.4 µs	367.6 µs	-30.53%
❌	Simulation	compare[58]	245.5 µs	352.3 µs	-30.31%
❌	Simulation	compare[59]	250.8 µs	359.3 µs	-30.2%
❌	Simulation	compare[57]	246.1 µs	350.9 µs	-29.86%
❌	Simulation	compare[54]	236.2 µs	335.4 µs	-29.58%
❌	Simulation	compare[55]	241.1 µs	342.2 µs	-29.54%
❌	Simulation	compare[52]	230 µs	325.5 µs	-29.35%
❌	Simulation	compare[48]	212.2 µs	300.3 µs	-29.32%
❌	Simulation	compare[53]	236 µs	333.3 µs	-29.2%
❌	Simulation	compare[50]	226.9 µs	318.6 µs	-28.78%
❌	Simulation	compare[51]	232 µs	325.6 µs	-28.75%
❌	Simulation	compare[49]	227.5 µs	317.4 µs	-28.32%
❌	Simulation	compare[46]	217.9 µs	302.2 µs	-27.88%
❌	Simulation	compare[47]	222.8 µs	308.9 µs	-27.88%
❌	Simulation	compare[44]	211.3 µs	291.9 µs	-27.62%
❌	Simulation	compare[45]	218.2 µs	300.7 µs	-27.41%
...	...	...	...	...	...

ℹ️ Only the first 20 benchmarks are displayed. Go to the app to view all benchmarks.

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

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_{Comparing fuzzer-fix/issue-8249 (f1f062b) with develop (5e3aedb)}