chore: update dependencies (ahocorasick v0.3.1, x/sys v0.47.0)

[kolkov]

Summary

Update all direct dependencies to latest versions.

Dependency	From	To	Type
github.com/coregx/ahocorasick	v0.3.0	v0.3.1	PATCH — LeftmostLongest early return perf
golang.org/x/sys	v0.40.0	v0.47.0	PATCH — CPU detection

Test plan

• go build ./... — clean
• go test ./... — all 11 packages pass
• CI: tests on 3 OS
• CI: benchmark comparison

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!

[github-actions]

Benchmark Comparison

Comparing main → PR #168

Summary: geomean 84.88n 87.03n +2.53%

⚠️ Potential regressions detected:

geomean                    84.88n         87.03n        +2.53%
geomean                               ³                +0.00%               ³
geomean                               ³                +0.00%               ³
geomean              31.95n         32.14n        +0.60%
geomean                         ³                +0.00%               ³
geomean                         ³                +0.00%               ³
AhoCorasickVsStdlib/coregex_Find-4                      19.32µ ± ∞ ¹    20.39µ ± ∞ ¹    +5.53% (p=0.008 n=5)
AhoCorasickVsStdlib/stdlib_Find-4                       136.0µ ± ∞ ¹    147.5µ ± ∞ ¹    +8.44% (p=0.008 n=5)
AhoCorasickVsStdlib/coregex_Count-4                     20.42µ ± ∞ ¹    21.64µ ± ∞ ¹    +6.00% (p=0.008 n=5)
AhoCorasickVsStdlib/stdlib_FindAllIndex-4               138.8µ ± ∞ ¹    148.1µ ± ∞ ¹    +6.66% (p=0.008 n=5)

Full results available in workflow artifacts. CI runners have ~10-20% variance.
For accurate benchmarks, run locally: ./scripts/bench.sh --compare