refactor(cli): plain-text console output; drop rich; quiet transformers

cli.py now emits plain ASCII through a small click.echo shim
(_Console / _Table / _Progress) instead of rich: no colors, markup tags,
panels, progress bar, or Unicode glyphs (Warning: / -> / ... and dropped
checkmark/cross marks). identify and metadata tables render as indented
plain lines.

- drop rich from dependencies (pyproject.toml + uv.lock)
- __init__: set TRANSFORMERS_VERBOSITY=error (setdefault) plus a warnings
  filter so the transformers Siglip2ImageProcessorFast deprecation no
  longer prints at CLI startup (it fires from the eager noai import)
- TestGpuHintMarkup: the [gpu] hint is now printed verbatim; docstring updated
- CLAUDE.md: replace the obsolete rich-markup lesson, note the verbosity fix

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tests/test_cli.py

@@ -526,8 +526,8 @@ class TestBatchCommand:
 
 
 class TestGpuHintMarkup:
-    """The GPU-extra install hint must survive rich markup (the ``[gpu]`` token
-    is otherwise parsed as a style tag and silently dropped)."""
+    """The GPU-extra install hint must reach the user with the ``[gpu]`` token
+    intact (plain output prints it verbatim, with no markup parsing)."""
 
     def test_invisible_install_hint_keeps_gpu_extra(self, runner, sample_png):
         with patch("remove_ai_watermarks.invisible_engine.is_available", return_value=False):