Match interceptor regexes against conservative, raw shell command segments
in addition to the complete command, so anchored rules can detect commands
after &&, ||, ;, |, &, and newlines without treating quoted or escaped text
as commands.
Add extractFlatShellCommandSegments() to preserve source text for
user-configured regexes, unlike the token-based approval matcher.
Add skipShellWord() and environment-assignment stripping so rules can match
commands prefixed with NAME=value assignments. Preserve the original command
in interception errors after extracting a leading cd command.
Vincent Huang
edb0deebb4