Delete every knob the fixed profiles cannot honor

The CLI still advertised --model, --steps, --guidance-scale, --device and a
deprecated --auto. Each pinned a value the two surviving profiles fix -- the
model stack, the per-stage distilled schedule, CFG 1.0, CUDA -- so the only
outcome any of them had was an error raised several frames below the caller,
under a message naming an internal profile. A flag whose sole result is a
refusal is worse than no flag: it advertises a capability that does not exist,
and it lets a wrapper thread a value that will silently do nothing. They are
gone from the parser, from InvisibleEngine, and from WatermarkRemover, so the
failure is now a TypeError or a Click "No such option" at the point the caller
can act on.

The install hint was wrong in the same way. is_available() checked torch and
diffusers, then told the user to install [diffusion] -- which contains neither
DiffSynth nor the Z-Image face stage both profiles run. Following the advice
produced a second, different failure. The module list and the extra name now
live once in watermark_profiles (REMOVAL_MODULES, INVISIBLE_EXTRA) and are read
by both the CLI gate and the remover's precondition, which cannot drift apart
because they are the same tuple.

The adaptive-polish default moved out of the argument parser. It was resolved by
reading Click's parameter source, which put per-profile data in the CLI layer,
left the engine declaring the opposite default (False vs True) so a library
caller and a CLI caller on one profile got different output, and lost the polish
entirely for anything that supplies the flag non-interactively. The flag is now
tri-state (default=None) and resolve_adaptive_polish owns the per-profile
answer. The seed follows the same rule: the CLI stopped pre-resolving it.

Dead code removed with it: six scan_*_video wrappers and the _scan_video helper
none of them had a caller for, PNG_METADATA_KEYS, feather_region_composite and
the remover region path that was only reachable from a no-caller convenience
wrapper, remove_watermark_batch on both layers, try_empty_device_cache, the
_generate/_run_qwen_zimage pass-through pair, self.model_id, and the _internal
PEP 562 shim that no caller ever went through. get_device now answers cuda or
cpu only: mps and xpu travelled one frame to the same CUDA-only refusal while
costing a device probe each, and that refusal now names the resolved device, so
device=None on a CUDA-less host says 'cpu' rather than 'None'. The XPU wheel
index went with them.

Docs: README, cli, installation, python-api, supported-signals,
known-limitations and module-internals all still described the removed profiles,
the CPU/MPS/XPU ladder, a `default`->`sdxl` alias, and the wrong extra.
known-limitations still listed the retired SDXL strength ladder as current.
scripts/smoke_matrix.py and real_examples_e2e.py drove --device mps.

Next release is 0.25.0, not a patch: this removes public parameters and
narrows a published extra on top of the released 0.24.0.

pre-commit: 1) maintain.sh - exit 0 (1091 tests, Pyright 0 errors, no
vulnerabilities); 2) /simplify - 4 agents, 11 findings applied, 2 skipped
(dropping the `device` parameter entirely, which raiw-app pins; folding
diffsynth into the `diffusion` extra, which video-only callers do not need);
3) docs sync - grepped every removed identifier across README, docs/, scripts/,
.claude/; updated 9 docs; 4) CLAUDE.md - added the no-error-only-knobs rule to
.claude/rules/development.md

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

tests/test_tiling.py

@@ -15,7 +15,6 @@ from PIL import Image
 from remove_ai_watermarks._internal.tiling import (
     Tile,
     _axis_positions,
-    feather_region_composite,
     feather_weights,
     plan_tiles,
     run_tiled,
@@ -139,72 +138,3 @@ class TestRunTiled:
         image = Image.new("RGB", (1500, 1100), (200, 100, 50))
         out = run_tiled(generate, image, tile_size=1024, overlap=128)
         assert out.size == (1500, 1100)
-
-
-class TestFeatherRegionComposite:
-    """Region-targeted compositing for AI-enhanced composites: only the AI box is
-    regenerated, the real photo outside it stays pixel-exact (roadmap P1#8)."""
-
-    @staticmethod
-    def _frames(h=200, w=300):
-        base = np.full((h, w, 3), 80, np.uint8)
-        regenerated = np.full((h, w, 3), 200, np.uint8)
-        return base, regenerated
-
-    def test_outside_box_is_pixel_exact(self):
-        base, regen = self._frames()
-        out = feather_region_composite(base, regen, (100, 60, 80, 50), feather=8)
-        # Far corners are well outside the box -> identical to base.
-        assert np.array_equal(out[:50, :80], base[:50, :80])
-        assert np.array_equal(out[150:, 220:], base[150:, 220:])
-
-    def test_interior_equals_regenerated(self):
-        base, regen = self._frames()
-        out = feather_region_composite(base, regen, (100, 60, 80, 50), feather=8)
-        # Deep interior of the box (past the feather ramp) is fully regenerated.
-        assert np.array_equal(out[80:90, 130:150], regen[80:90, 130:150])
-
-    def test_hard_paste_when_no_feather(self):
-        base, regen = self._frames()
-        out = feather_region_composite(base, regen, (100, 60, 80, 50), feather=0)
-        assert np.array_equal(out[60:110, 100:180], regen[60:110, 100:180])
-        assert np.array_equal(out[:60], base[:60])
-
-    def test_seam_is_monotonic_ramp(self):
-        base, regen = self._frames()
-        out = feather_region_composite(base, regen, (100, 60, 80, 50), feather=10).astype(np.float32)
-        # Along a horizontal line crossing the left edge, values rise from base(80)
-        # toward regenerated(200) monotonically through the feather band.
-        row = out[85, 100:115, 0]
-        assert row[0] < row[-1]
-        assert np.all(np.diff(row) >= -1e-3)
-
-    def test_dtype_preserved(self):
-        base, regen = self._frames()
-        out = feather_region_composite(base, regen, (50, 50, 40, 40), feather=4)
-        assert out.dtype == base.dtype
-
-    def test_grayscale_2d_supported(self):
-        base = np.full((100, 120), 30, np.uint8)
-        regen = np.full((100, 120), 220, np.uint8)
-        out = feather_region_composite(base, regen, (40, 30, 30, 30), feather=4)
-        assert out.shape == base.shape
-        assert np.array_equal(out[:30], base[:30])
-
-    def test_empty_or_offimage_box_returns_base(self):
-        base, regen = self._frames()
-        assert np.array_equal(feather_region_composite(base, regen, (0, 0, 0, 0)), base)
-        assert np.array_equal(feather_region_composite(base, regen, (500, 500, 40, 40)), base)
-
-    def test_box_clamped_to_image_bounds(self):
-        base, regen = self._frames()
-        # Box overhangs the bottom-right; only the in-image part is composited.
-        out = feather_region_composite(base, regen, (280, 180, 60, 60), feather=0)
-        assert np.array_equal(out[180:, 280:], regen[180:, 280:])
-        assert out.shape == base.shape
-
-    def test_shape_mismatch_raises(self):
-        base, _ = self._frames(200, 300)
-        bad = np.full((100, 100, 3), 200, np.uint8)
-        with pytest.raises(ValueError, match="shape mismatch"):
-            feather_region_composite(base, bad, (10, 10, 20, 20))