Fix what the verification pass found in the knob removal

An adversarial review of 52b2c11 (five independent audits, each finding put to
two skeptics, plus a completeness critic) found four defects that commit
introduced and several stale claims it should have caught.

The install hint no longer installs -- again. Folding five hints into one
INVISIBLE_EXTRA constant dropped the shell quoting the originals had, so the
printed remediation was `pip install remove-ai-watermarks[qwen-zimage]`. Bare
brackets are a glob in zsh, the macOS default shell: it dies with "no matches
found" before pip runs. That is the exact failure 52b2c11 existed to stop
producing, reintroduced in a different form by a bulk replace. The constant is
quoted now, and a test asserts the quotes rather than the bare substring -- the
old assertions passed either way, which is why nothing caught it.

Three tests were not guarding what they claimed:

- The commit's headline behaviour change, per-profile polish resolution inside
  the engine, had no test at all. Rebinding resolve_adaptive_polish to the
  pre-commit `bool(value)` left the full suite green. Now covered by a test that
  drives the real engine and observes whether humanizer.adaptive_polish ran;
  that mutation now fails it.
- TestAvailability still asserted the pre-commit (torch, diffusers) contract, so
  in a diffusion-only environment it was simply wrong, and comparing each gate to
  a tuple copied from itself could never catch the two gates disagreeing -- the
  drift the shared REMOVAL_MODULES was introduced to prevent. Replaced with a
  test that simulates each module's absence and requires BOTH gates to close.
- Both CUDA-refusal guards skipped in every environment, including CI: they were
  gated on the diffusion stack, which no CI job installs. The refusal fires
  before any torch attribute is read, so they now run everywhere; only the dtype
  assertion keeps its skip.

Also: the retired-knob test covered `invisible` but not `all` or `batch`, though
all three declared those options separately; and smoke_matrix.py still called
remove_watermark(region=...), a parameter 52b2c11 deleted, with the resulting
TypeError swallowed into a skip by a broad except.

Stale documentation the previous sweep missed: known-limitations still described
an MPS out-of-memory fallback and a lighter-pipeline escape that no code can
produce; module-internals declared Canny thresholds of 100/200 as a compatibility
contract while the code uses 13/64, attributed enable_model_cpu_offload to
deleted profiles, and still warned that the engine and CLI defaults differ (this
commit's predecessor made them identical); cli.md gated `all` on the `diffusion`
extra; python-api claimed "cuda" was the only accepted explicit device when
"auto" is too. The claim that `device` is not a parameter was wrong in both
module-internals and .claude/rules/development.md -- it is one, deliberately, and
now says so. `--cpu-offload` help and the pipeline's CUDA guard both still
pointed at MPS.

Not fixed here, reported instead -- both are outside this repo:
- ComfyUI-remove-ai-watermarks nodes.py:332 passes num_inference_steps and
  guidance_scale (plus min_resolution/upscaler from bf4bfc1). distribute.yml's
  comfyui job runs on every release and fails the release if the node sync fails,
  so 0.25.0 needs that node updated first.
- raiw-app modal_app.py:422-425 forwards the same two kwargs into
  remove_watermark. Latent: it is pinned to 1a77e24 and nothing supplies a value
  today, so it fires on the next pin bump.

pre-commit: 1) maintain.sh - exit 0 (1093 tests, Pyright 0 errors, no
vulnerabilities); 2) /simplify - not re-run, this commit is the applied output of
a five-dimension adversarial review; 3) docs sync - grepped MPS/mps, the extras
names and every symbol touched across README, docs/, scripts/, .claude/; updated
6 docs; 4) CLAUDE.md - corrected the device claim in .claude/rules/development.md
and added the shell-quoting rule

Verified by execution, not assertion: smoke_matrix --quick 51 pass / 0 fail,
_knob_rows driven directly 10 pass / 0 fail / 7 skip (no CUDA), the install hint
rendered and round-tripped through zsh, and each new test confirmed to fail
under the mutation it is meant to catch.

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

src/remove_ai_watermarks/_internal/qwen_zimage_pipeline.py

@@ -636,8 +636,9 @@ class QwenZImagePipeline:
     def _require_cuda(self) -> None:
         if self.device != "cuda":
             raise RuntimeError(
-                "The qwen-zimage pipeline is CUDA-only. Its Qwen-Image-2512 and "
-                "Z-Image models do not fit the supported MPS path."
+                "The qwen-zimage pipeline is CUDA-only; there is no CPU or MPS path "
+                "for it. WatermarkRemover already refuses a non-CUDA device, so "
+                "reaching this guard means the pipeline was constructed directly."
             )
 
     def _vram_limit(self) -> float | None:

src/remove_ai_watermarks/_internal/watermark_profiles.py

@@ -34,7 +34,11 @@ PROFILE_CHOICES = (QWEN_ZIMAGE_PROFILE, SDXL_ZIMAGE_PROFILE)
 # the CLI passed on a torch+diffusers environment and the run then died at the
 # DiffSynth face stage, telling the user to install an extra that does not contain it.
 REMOVAL_MODULES = ("torch", "diffusers", "diffsynth")
-INVISIBLE_EXTRA = "remove-ai-watermarks[qwen-zimage]"
+# Shell-quoted, because this string is printed as a command the user copy-pastes.
+# Bare brackets are a glob in zsh (the macOS default shell): an unquoted
+# ``pip install remove-ai-watermarks[qwen-zimage]`` dies with "no matches found"
+# before pip ever runs -- another install hint that does not install.
+INVISIBLE_EXTRA = "'remove-ai-watermarks[qwen-zimage]'"
 
 # qwen-zimage's output already matches the input's detail level, so polishing it is a
 # no-op at best. sdxl-zimage's global pass leaves the softer output the polish exists

src/remove_ai_watermarks/cli.py

@@ -286,8 +286,7 @@ _cpu_offload_option = click.option(
     help=(
         "Offload model components to CPU between CUDA calls instead of keeping the "
         "whole pipeline in VRAM, at the cost of speed. For qwen-zimage, forces the "
-        "face stack to offload instead of using automatic residency. No effect on "
-        "cpu/mps."
+        "face stack to offload instead of using automatic residency."
     ),
 )