fix(pipeline): run Sharpen and the crop in their documented order (#109)

[StuartCameronCode]

Fixes #109.

What was wrong

• The Sharpen pass showed a warning that it "runs before Noise Reduction, so the denoiser will soften much of this again". That was false: Sharpen already ran after Noise Reduction, Chroma Denoise, Dehalo, Deblock, Deband and Anti-Aliasing.
• Sharpen was not last, though. It ran ahead of Chroma Fixes, Colour Correction, Stabilize and Crop & Resize, so a downscale softened the sharpened edges again and an upscale enlarged the sharpening halos.

What changed

• Removed the false warning from pass_advice.dart.

• Moved Sharpen to after Crop & Resize and before Film Grain, in both .vpy templates, the Rust and Dart pass orders, and the pass list (it now sits at the top of "Finishing").

• README and docs/ENGINEERING_NOTES.md record the new order and why.

• Moved the crop from the top of both templates (ahead of Deinterlace) to directly before the resize, so the order is Stabilize → Rotate / Flip → Crop → Resize → Sharpen. Until now a crop could not remove the edges Stabilize exposes, although the comments, descriptions and tests all said it did.

Documentation

• The README's "The filter pipeline" table is now numbered in the order the filters run, with notes on what a table cannot show: Crop & Resize is one step with the crop first, and custom code, colour conversion and borders follow the filters.
• readme_pipeline_order_test.dart fails if that table and PassListPanel.stages disagree.
• The README, code comments and in-app descriptions already said Stabilize runs last before cropping; that is now true (see below).

Behaviour changes

• Presets and saved jobs that combine Sharpen with a resize, Stabilize, Chroma Fixes or Colour Correction render slightly differently than before.
• Crop sides now refer to the picture after a rotation; they used to refer to the source. Saved jobs and presets combining a quarter turn with a crop will crop different edges.
• Every pass before the crop works on the uncropped frame: slower with a crop, Edge Repair rebuilds the uncropped edge, and the automatic measurements (levels, white balance, chroma alignment) see the area the crop will remove, e.g. head-switching noise on a VHS capture. The effect on those measurements was not measured.
• Sharpen now works at the output resolution: slower when upscaling, faster when downscaling.

Testing

• flutter test --exclude-tags heavy: passes.
• cargo test: passes except subtitle_integration_test, which needs whisper-cli and it is not installed locally.
• Heavy: a new test in integration_new_passes_test.dart encodes each sharpen method after a resize and checks the output size; it and integration_filter_pipeline_test.dart pass. The rest of the heavy suite was not run locally.
• test_110 (Rust) and pass_list_stages_test.dart now pin Sharpen after the resize and before the grain; pass_advice_test.dart asserts the Sharpen + Noise Reduction pair is silent.
• Not covered: no preview was rendered with Sharpen after a resize. The preview template got the same move, but only the encode path was exercised.

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https://claude.ai/code/session_014GLXdGLfPwgYjW1AkonGqN