Reject the uncalibrated text-manifest tiling and verify Content Seal transforms

Tiled diffusion was never provider-oracle calibrated with verified text
restoration: the tiled VAE donor path ran anyway and produced results no
oracle had certified. The combination is now rejected at both the
pipeline and the engine seam (ValueError with the reason), and the CLI
help no longer implies support. The invisible help is generalized and
the metadata container list corrected (MKA/OGA/Opus/AAC).

scripts/contentseal_transforms.py reproduces the deterministic crop,
resize, and JPEG variants of the Content Seal corpus from manifest.csv,
hash-verifying every output; its README gains scripts/README.md context
and new data tests. The corpus README is honest about the one crop the
daily oracle limit left unchecked, and the eval CSVs carry the updated
verdicts. The byte-scan SynthID suppression hoists its soft-binding
lookup so the guard is computed once.

Staged on top of 0.33.1; no version bump in this commit.

tests/test_liblib_engine.py

@@ -1,4 +1,4 @@
-"""Tests for the LibLibAI ("LibLibAI" wordmark) visible-watermark engine.
+"""Tests for the LiblibAI ("LiblibAI" wordmark) visible-watermark engine.
 
 Every tuned constant in ``liblib_engine`` was measured on the 15-frame vendor
 cohort (2026-07-22); these tests pin the load-bearing ones: the bottom-CENTER
@@ -24,7 +24,7 @@ _MARK_FRAC = 0.10  # measured wordmark width, fraction of the frame WIDTH
 
 
 def _compose(w: int, h: int, bg: float = 100.0):
-    """Composite a triangle logo + the LibLibAI wordmark, bottom-center."""
+    """Composite a triangle logo + the LiblibAI wordmark, bottom-center."""
     img = np.full((h, w, 3), bg, np.float32)
     at = _alpha_template()
     gw = int(_MARK_FRAC * w)
@@ -112,8 +112,8 @@ class TestDetectAndMask:
         assert eng.footprint_mask(img) is None
 
     def test_confident_liblib_detection_suppresses_the_jimeng_pill(self):
-        # A LibLibAI image is TC260 too but is not Jimeng-basic: like Doubao/Qwen/
-        # Kling/RunningHub/Baidu, a confident LibLibAI detection must veto the pill.
+        # A LiblibAI image is TC260 too but is not Jimeng-basic: like Doubao/Qwen/
+        # Kling/RunningHub/Baidu, a confident LiblibAI detection must veto the pill.
         # It was the one mark the hand-written veto list in ``_keep_pill`` missed.
         from remove_ai_watermarks.watermark_registry import _keep_pill