test : add unit tests for hashcat plugin parser

[tmdeveloper007]

Summary of What Needs to be Done:
Add a dedicated unit test file for the hashcat plugin parser in plugins/hashcat/parser.py. The parser currently has no test coverage.

The hashcat parser processes hashcat output and extracts cracked passwords, hash information, and session statistics.

Changes that Need to be Made:
Create testing/backend/unit/test_hashcat_plugin.py with:

• Tests for parse() with various hashcat output formats:
  • Successful crack with hash and password
  • Multiple cracked hashes in output
  • Session statistics in output
  • Empty output
  • Malformed/non-hashcat output
  • Return value structure validation (findings, count, rows)
• Add a fixtures directory: testing/backend/unit/fixtures/hashcat/ with sample hashcat outputs

Impact that it would Provide:

• Covers a currently untested plugin parser
• Enables regression detection for hash parsing logic changes
• Follows the existing plugin unit test pattern

Note: This task is being handled by tmdeveloper007 — please assign to that account when picking it up.