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.

scripts/README.md

@@ -0,0 +1,68 @@
+# Maintainer scripts
+
+These scripts are development and evaluation tools, not installed CLI commands. Run
+them from the repository root with `uv run python scripts/<name>.py --help`. Inputs
+under `.local-eval/` and generated reports remain untracked unless a data README
+explicitly names a tracked canonical result.
+
+## Audits and release checks
+
+| Script | Purpose |
+| --- | --- |
+| `corpus_gap_scan.py` | Compare a local image corpus with the library's `identify` results. |
+| `detection_timing.py` | Record per-method metadata and verdict timings. |
+| `detection_timing_report.py` | Aggregate timing records by method and segment. |
+| `fidelity_metrics.py` | Compute objective image-fidelity metrics for paired outputs. |
+| `invisible_quality_audit.py` | Pair originals and invisible-removal outputs for quality review. |
+| `metadata_removal_audit.py` | Check metadata detection/removal parity over a corpus. |
+| `pill_gate_audit.py` | Measure the Jimeng pill detector on the product path. |
+| `real_examples_e2e.py` | Run end-to-end confidence checks over local examples. |
+| `record_parity_audit.py` | Compare record-based and file-based identification. |
+| `resource_ceilings.py` | Measure peak RSS and runtime for fill backends. |
+| `robustness_suite.py` | Exercise CLI failures on adversarial and degenerate inputs. |
+| `sidecar_regression.py` | Compare current identification with recorded sidecars. |
+| `smoke_matrix.py` | Exercise CLI parameter choices on real local data. |
+| `video_fidelity_probe.py` | Compare delivered video fidelity with its source. |
+| `visible_eval.py` | Benchmark registered visible-mark detectors. |
+| `visible_removal_audit.py` | Audit visible-removal results over a local corpus. |
+
+## Calibration and corpus preparation
+
+| Script | Purpose |
+| --- | --- |
+| `contentseal_transforms.py` | Reproduce and hash-check deterministic Content Seal variants. |
+| `detector_response.py` | Measure detector response over mark size, contrast, background, and aspect. |
+| `fill_quality.py` | Measure visible-fill quality against constructed ground truth. |
+| `ladder_headroom.py` | Measure recall cost from the coarse scale ladder. |
+| `synthid_corpus.py` | Ingest and inspect the local SynthID reference corpus. |
+| `vendor_cohort_harvest.py` | Partition TC260 carriers by producer code. |
+| `vendor_mark_calibrate.py` | Calibrate a candidate vendor text detector. |
+| `visible_alpha_solve.py` | Rebuild visible-watermark alpha assets from controlled captures. |
+| `visible_groundtruth.py` | Consolidate blinded contact-sheet labels into ground truth. |
+| `visible_positives.py` | List corpus images carrying a registered visible mark. |
+| `visible_recall_sample.py` | Build an unbiased blinded sample for recall measurement. |
+| `visible_sheets.py` | Build blinded contact sheets for relaxation candidates. |
+
+## Research and diagnostic prototypes
+
+| Script | Purpose |
+| --- | --- |
+| `cjk_tail_probe.py` | Test a generic template for otherwise uncovered CJK labels. |
+| `controlnet_sweep.py` | Sweep the historical ControlNet removal prototype. |
+| `infer_text_lines.py` | Draft stable source-text lines without modifying pixels. |
+| `qwen_scrub_prototype.py` | Probe low-strength Qwen regeneration on a GPU. |
+| `selective_text_restoration.py` | Evaluate text restoration over a scrubbed image. |
+| `synthid_pixel_probe.py` | Run the experimental local SynthID carrier probe. |
+| `video_synthid_sweep.py` | Build oracle-gated video regeneration candidates. |
+
+## Generated assets
+
+| Script | Purpose |
+| --- | --- |
+| `render_pill_silhouette.py` | Render the synthetic Jimeng pill silhouette. |
+| `render_vendor_silhouettes.py` | Render synthetic vendor text-mark silhouettes. |
+
+## Shared helpers
+
+`_plain_console.py` provides plain-text fallbacks for Rich output, and
+`_text_eval.py` contains normalization helpers shared by text-evaluation scripts.