Handle Windows .cmd shim resolution via spawnSync with strict path
validation. Removes shell:true injection risk, uses strict equality,
and restores .cmd support with path injection guard.
Invoke hook scripts directly via require() when they export a
run(rawInput) function, eliminating one Node.js process spawn per
hook invocation (~50-100ms).
Includes path traversal guard, timeouts, error logging, PR review
feedback, legacy hooks guard, normalized filePath, and restored
findProjectRoot config detection with package manager support.