[Golopmoui3]

Fixes #57

Problem

Previously, when positional arguments were passed after the double-dash -- delimiter (e.g., prog build -- abc xyz for a command defined as build [config]), sade greedily consumed tokens following -- into command parameter slots (config became 'abc', leaving only ['xyz'] in opts._).

According to standard POSIX CLI conventions, -- indicates the end of command options/arguments, and any tokens past -- should remain intact in opts._ as unparsed operands rather than being shifted into command parameter positions.

Solution

1. Locate the double-dash delimiter in the raw slice: raw.indexOf('--').
2. Compute the count of arguments appearing past -- (post) and available before -- (pre = vals._.length - post).
3. Validate required arguments (<arg>) only against the pre argument pool.
4. For optional argument slots ([arg]), shift from vals._ only while pre > 0; otherwise assign undefined (void 0).
5. All arguments passed after -- remain preserved in opts._.

Testing

• Added regression test in test/index.js confirming:
  • parse(['node', 'cli.js', 'build', '--', 'abc', 'xyz']) produces config: undefined and opts._: ['abc', 'xyz'].
  • parse(['node', 'cli.js', 'build', 'myconf', '--', 'abc', 'xyz']) binds config: 'myconf' and preserves opts._: ['abc', 'xyz'].
  • parse(['node', 'cli.js', 'deploy', 'prod', '--', 'extra']) binds env: 'prod' and preserves opts._: ['extra'].
• All 602 tests pass across the entire test suite (test/index.js, test/usage.js, test/utils.js).