BL-15958 Expand full-bleed page-size support and dotImpose handoff

[hatton]

[Claude Fable 5 following a prompt from Hatton]

Part 2 of 3 of the updated BL-15958 work, split out of #7713.

Tracker: BL-15958

What this does

• Adds DistFiles/pageSizesLookup.json, generated at build time by src/content/pageSizes.ts, so C# code can look up trim dimensions for any layout. SizeAndOrientation.TryGetSizeInMillimeters reads it.
• EpubMaker.GetPageDimensions now uses that lookup instead of parsing pageSizes.json itself.
• The PDF pipeline supports full bleed for all page sizes: MakePdfUsingExternalPdfMakerProgram sizes full-bleed pages from the lookup, and PdfMaker writes explicit trim/bleed boxes before the dotImpose handoff.
• Booklet layouts keep trim-sized source pages (PublishModel.GetPrintingWithFullBleed).
• Updates sillsdev.dotImpose to 2.6.7-test, published to nuget.org from sillsdev/dotImpose master. The new library deprecates NullLayoutMethod(insetTrimboxMillimeters); Bloom now uses the parameterless NullLayoutMethod() because the source PDF carries explicit boxes.

Follow-up before merge

The pin is a prerelease version (2.6.7-test). The dotImpose publish workflow fills its default suffix "test" even when the dispatch input is empty, so a release version needs a one-line workflow fix in that repo first. Then bump the pin here.

Relationship to the other parts

Independent of the other two PRs; based on master. The siblings are the edge-to-edge theme PR (#8262) and the edit-mode crop-marks PR (#8264).

Verification

• The full front-end build passes and regenerates the lookup file.
• The PdfMakerTests and MakePdfUsingExternalPdfMakerProgramTests fixtures pass: 25 of 25, including the full-bleed crop-marks trim test that failed against dotImpose 2.6.2.

🤖 Generated with Claude Code

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This change is 

Devin review

[greptile-apps]

Greptile Summary

This PR centralizes page-size dimensions in a generated millimeter lookup and expands the PDF full-bleed pipeline to additional paper sizes and the dotImpose handoff.

• Generates and distributes pageSizesLookup.json from the canonical page-size configuration.
• Reuses the lookup for ePub dimensions and full-bleed PDF sizing.
• Reconstructs PDF trim, bleed, crop, and art boxes before imposition.
• Keeps booklet source pages trim-sized and adds PDF sizing/box tests.

Important Files Changed

Filename	Overview
src/BloomExe/Book/SizeAndOrientation.cs	Adds lazy loading and orientation-aware access to generated millimeter dimensions; the two new public methods need documentation comments.
src/content/pageSizes.ts	Extends the existing page-size build step to deterministically generate a C#-consumable lookup with configured, ISO-series, and square aliases.
src/BloomExe/Publish/PDF/MakePdfUsingExternalPdfMakerProgram.cs	Replaces the fixed full-bleed size switch with lookup-backed trim dimensions plus a 3 mm bleed on every edge.
src/BloomExe/Publish/PDF/PdfMaker.cs	Recreates page boxes before dotImpose and supplies a consistent 3 mm full-bleed inset; compatibility with the currently published dotImpose behavior remains explicitly acknowledged by the PR.
src/BloomExe/Publish/PDF/PublishPdfApi.cs	Automatically synchronizes crop-mark generation with the selected book's print-bleed preference.
src/BloomExe/Publish/PublishModel.cs	Restricts bleed-sized source pages to non-booklet output so imposed booklet layouts continue using trim dimensions.
src/BloomExe/Publish/Epub/EpubMaker.cs	Reuses the generated millimeter lookup and converts dimensions to CSS pixels for ePub output.
src/BloomTests/Publish/PDF/PdfMakerTests.cs	Adds bleed-offset and dotImpose TrimBox coverage, including the dependency behavior explicitly called out as unresolved.
src/BloomTests/Publish/PDF/MakePdfUsingExternalPdfMakerProgramTests.cs	Covers expanded portrait, landscape, square, and unsupported full-bleed page-size handling.

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