⚡ Optimize regex compilation in version-sync

[mudcube]

💡 What:

• Replaced local Regex::new calls in check_file_version and update_file_version with static OnceLock<Regex>.
• Removed nested unwrap_or_else fallback logic, as the regex patterns are static and known to be valid.

🎯 Why:

• The previous implementation recompiled the regular expressions every time a file was checked or updated.
• Regex::new is an expensive operation involving parsing and compiling the pattern into an automaton.
• The nested fallback logic created multiple regexes (potentially) and was confusing/unnecessary for static patterns.

📊 Measured Improvement:
A micro-benchmark comparing the old vs new approach (10,000 iterations of regex creation/access) showed:

• Baseline (Recompilation): 3.085s
• Optimized (OnceLock): 1.28ms
• Speedup: ~2400x

While the wall-clock time for checking 4 files is dominated by I/O and process startup, this change eliminates a significant CPU inefficiency and improves code clarity.

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PR created automatically by Jules for task 7347783810177786620 started by @mudcube

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