fix regex \d, \w, \s character classes

[cs01]

Summary

• \d, \w, \s (and their negated forms \D, \W, \S) were silently matching literal characters instead of their character classes — e.g., /\d+/ matched the letter "d" instead of digits
• Root cause: ChadScript uses POSIX regcomp/regexec which doesn't support Perl-style shorthand classes. \d in POSIX means literal "d"
• Fix: translate JS regex shorthands to POSIX equivalents before compilation (\d → [0-9], \w → [a-zA-Z0-9_], \s → [ \t\n\r], etc.)
• Handles shorthands both inside and outside bracket expressions

Test plan

• New test fixture regex-character-classes.ts covering all 6 shorthands, negated forms, quantifiers, and test() method
• All 769 tests pass
• Self-hosting verification passes

🤖 Generated with Claude Code

[github-actions]

Benchmark Results (Linux x86-64)

Benchmark	C	ChadScript	Go	Node	Bun	Place
Binary Trees	1.673s	1.271s	2.690s	1.290s	1.068s	🥈
Cold Start	0.8ms	0.9ms	1.2ms	25.6ms	9.7ms	🥈
Fibonacci	0.909s	1.410s	1.733s	3.397s	2.062s	🥈
File I/O	0.089s	0.094s	0.087s	0.176s	0.185s	🥉
JSON Parse/Stringify	0.004s	0.005s	0.016s	0.015s	0.007s	🥈
Matrix Multiply	0.489s	0.741s	0.788s	0.426s	0.399s	#4
Monte Carlo Pi	0.440s	0.440s	0.458s	2.607s	6.493s	🥇
N-Body Simulation	1.750s	2.253s	2.289s	2.415s	3.327s	🥈
Quicksort	0.246s	0.283s	0.242s	0.292s	0.261s	#4
SQLite	0.322s	0.365s	—	0.418s	0.391s	🥈
Sieve of Eratosthenes	0.015s	0.027s	0.020s	0.042s	0.036s	🥉
String Manipulation	0.008s	0.044s	0.016s	0.040s	0.030s	#5

CLI Tool Benchmarks

Benchmark	ChadScript	grep	node	xxd	Place
Hex Dump	0.431s	—	1.007s	0.138s	🥈
Recursive Grep	0.022s	0.012s	0.100s	—	🥈