[GOOD FIRST ISSUE] Add a --verbose/-v flag as a shortcut for DOCKSEC_LOG_LEVEL=INFO

[advaitpatel]

Background

Split out from #52. DOCKSEC_LOG_LEVEL already exists as an env-var override for log verbosity (see docksec/utils.py:get_custom_logger), but there's no CLI flag for it — a user has to know the env var exists and set it separately from the docksec invocation.

Task

Add a -v/--verbose flag to the argparse parser in docksec/cli.py that is equivalent to setting DOCKSEC_LOG_LEVEL=INFO for the run (do this by setting os.environ["DOCKSEC_LOG_LEVEL"] = "INFO" early in main(), before any logger is created — follow the same pattern already used for --provider/--model writing to LLM_PROVIDER/LLM_MODEL env vars around cli.py:78-80).

Acceptance criteria

• docksec Dockerfile --scan-only -v shows INFO-level log lines on stderr that are normally suppressed in CLI mode
• Without -v, behavior is unchanged (still defaults to ERROR-only in CLI mode)
• An explicit DOCKSEC_LOG_LEVEL env var set by the user still takes priority over -v (i.e. don't clobber it if already set)
• --help documents the flag
• README's flag list is updated
• A test in tests/test_cli.py covers the flag being parsed and setting the env var as expected

Pointers

• docksec/cli.py — argparse setup, look at how --compact-output sets DOCKSEC_COMPACT_OUTPUT
• docksec/utils.py:get_custom_logger — the level resolution logic this flag needs to influence

[Shouryaverma19]

Hi! I would love to implement the --verbose/-v flag shortcut as detailed in the acceptance criteria. Could you please assign this issue to me? Thanks!

[ahfoysal]

Implemented #129. PR here: #144