Enhance .env parsing for inline comments with leading whitespace

[udithavithanage]

This pull request improves the parsing of inline comments in environment variable files, especially around handling the # character in values. The main change is to correctly distinguish between # as part of a value and # as the start of a comment, depending on whether it is preceded by whitespace. This is reflected in both the parser logic and expanded test coverage.

Parsing improvements

• Updated the LINE regular expression in lib/main.js to treat # as the start of a comment only when it is preceded by whitespace.
• This allows # to be included as part of an environment variable value when it is not preceded by whitespace.

Examples

Input	Output
DB_PASS=test*&#secret123	test*&#secret123
DB_PASS=test #secret123	test
DB_PASS="test #secret123"	test #secret123

Test coverage enhancements

• Added new test cases in tests/.env, tests/.env.multiline, and corresponding assertions in tests/test-parse.js and tests/test-parse-multiline.js.
• Added coverage for:
  • Inline comments following values.
  • # characters embedded in unquoted values.
  • # characters inside quoted values.
  • Cases where # is and is not preceded by whitespace.

These tests verify that comments are parsed correctly while preserving # characters that are intended to be part of the value.

Fixes: #1018