Remove misleading `cr review --verbose` flag

[rianjs]

Problem

cr review --verbose is misleading. The flag name implies extra diagnostics/logging, but the current implementation primarily toggles IncludeNits, causing nits findings to appear in review output.

That makes the CLI contract unclear:

• --verbose sounds like an output/logging verbosity control.
• The actual behavior is domain-specific review policy: whether nit-level findings are rendered.
• It does not appear to enable additional stderr lifecycle/progress breadcrumbs.
• The README/help text says "Include nits in review output and emit additional diagnostics," but the code path we traced only wires the flag to IncludeNits.

Desired direction

Remove --verbose from cr review.

If nit visibility needs to remain configurable, replace it with an explicit flag/config surface, for example:

• --include-nits, or
• a reviewer profile policy for rendering nit-level findings.

Diagnostics/logging should have a separate, accurately named control if needed.

Acceptance criteria

• cr review --verbose is removed or deprecated with a clear migration path.
• Nit rendering is controlled by an explicit nits-specific option or profile policy if still needed.
• Help text and README no longer imply that --verbose controls diagnostics unless it actually does.
• Tests cover the replacement behavior and reject or warn on the removed/deprecated flag as appropriate.