[Subodh-17]

Summary

Fixes #57.

• Include exact dependency versions in OSV vulnerability query payloads when available.
• Parse exact == and === pins from requirements files.
• Handle package extras, inline comments and environment markers.
• Keep wildcard, ranged and unpinned dependencies on the existing unversioned query path.
• Preserve existing network-failure fallback behavior.

Tests

• CVE tests: 13 passed.
• Security subsystem tests: 81 passed.
• Ruff lint: passed.
• Ruff formatting: passed.
• Diff whitespace check: passed.

The full repository suite has known baseline environment failures involving optional tree-sitter grammars and Windows CLI behavior; these are documented separately and are not claimed as passing.