fix: treat bare parentheses as literals (Fixes #171)

[dyk1454683243-sudo]

Fixes #171

Problem

Unprefixed parentheses in a glob were compiled as regex capture groups, so a pattern like /foo/(a) matched /foo/a. That happens with or without noextglob: true, because noextglob only disables extglob prefixes (?(, *(, +(, @(, !() and does not change how a bare ( is compiled.

Bash treats bare ( / ) as literals. Expected match is false:

picomatch('/foo/(a)', { noextglob: true })('/foo/a')  // was true, want false
picomatch('/foo/(a)', { noextglob: false })('/foo/a') // was true, want false

Fix

In the parse/compile path, compile bare ( and ) as literal characters unless they form a real grouping construct:

• extglobs: ?(, *(, +(, @(, !(
• regex extensions: (?:, lookarounds
• groups whose body needs grouping (|, wildcards, slashes, escapes)
• quantified groups such as (a)* and (a)+

Inert wraps such as (a) stay literal, so /foo/(a) matches /foo/(a) and not /foo/a. Existing extglob behavior is unchanged.

Tests

• Regression coverage for the issue repro (with and without noextglob), plus checks that real extglobs still match
• Existing assertions that treated a plain (literal) wrap as a no-op capture group were updated to the bash-compatible result
• npx mocha --reporter spec: 1999 passing
• npx eslint on the touched files: clean

[dyk1454683243-sudo]

Withdrawing this PR while I clean up a high-volume open-PR backlog. Sorry for the noise — happy to come back later with a focused change if useful.