[Publication] Add a Lulu-compliant print and EPUB adapter pack

[szmyty]

Outcome

Add a versioned Lulu publication provider pack that turns a reviewed generic publication profile into validated Lulu upload candidates without hard-coding Lulu rules into Renderflow core.

This is the concrete commercial-publication consumer of:

• Stabilize Transform v2 and the plugin SDK around typed artifact I/O #357 — typed artifact/plugin SDK
• Add artifact validation, fidelity gates, and a capability conformance matrix #360 — validation and capability conformance
• Establish first-class adapter packs for the high-value open tool ecosystem #362 — provider adapter packs
• Evaluate and implement EPUB and KEPUB derivative support #344 — EPUB/KEPUB support
• Add a magazine publication profile and complete multi-channel release bundle #364 — magazine/multi-channel publication profile

Boundary

• Renderflow owns reusable planning, rendering, provider adapters, validation, provenance, and packaging.
• The content repository owns source pages, title/creator metadata, rights, identifiers, product choices, approval, credentials, upload, and publication.
• Lulu is a replaceable provider profile, not a core format.
• Initial scope produces and validates upload candidates. It does not log in, upload, order a proof, allocate an ISBN, or publish.

Versioned Lulu rule pack

• Pin a rule-pack version, observation date, and official source URLs.
• Separate print-direct, lulu-bookstore, global-distribution, pdf-ebook, and epub-distribution capability/eligibility results.
• Treat provider/channel restrictions as data with hard errors, warnings, and informational findings.
• Do not fetch changing rules during a deterministic build.
• Produce a machine-readable conformance report and human preflight report.
• Fail closed when a required rule is unknown or the requested product combination is unverified.

Print candidate

Generate and validate:

• single-page-layout interior PDF at exact selected trim/bleed geometry
• separate one-piece cover PDF using a user-supplied current Lulu template for the selected page count, paper, binding, and channel
• distinct Lulu Bookstore and Distribution covers where their spine geometry differs
• embedded fonts, flattened layers, rasterized vectors where required, high-resolution assets, correct page order, and no unintended blank pages
• no trim/bleed marks in distribution files
• title page followed by copyright page with metadata and print ISBN where distribution requires them
• exact title/subtitle/contributor/language/color metadata consistency
• correct barcode identity, dimensions, quiet background, and safe placement when enabled
• proof/contact sheet plus geometry, resolution, font, color, and metadata reports

Do not compute undocumented cover/spine geometry from guesses. Consume Lulu’s current generated template as an explicit input and record its digest.

EPUB candidate

Generate and validate:

• EPUB 3.3-compatible XHTML publication and EPUBCheck v5 evidence
• correct internal title, subtitle, contributors, language, identifier, and ebook ISBN metadata
• complete ordered navigation/TOC and page-list relationship to print where applicable
• RGB, legible, non-truncated images and text
• no unsupported interactive or fillable content in the Lulu distribution profile
• cover artifact appropriate for retailer metadata
• file-size policy with Lulu’s recommendations/limits represented accurately
• accessibility metadata and optional Ace by DAISY evidence
• explicit fixed-layout compatibility result per selected Lulu/retailer channel; do not silently convert or claim support

Support a faithful fixed-layout comic EPUB and an accessible companion/reflow branch when the canonical source permits it. Their roles and ISBN decisions remain separate and explicit.

Eligibility guardrails

• Validate trim, binding, paper, color, page count, language, ISBN, metadata, and channel eligibility before declaring an artifact upload-ready.
• Represent Lulu printing, Lulu Bookstore sale, Lulu Direct, Amazon eligibility, and Ingram/Barnes & Noble availability independently.
• Add a regression fixture showing that a 44-page color interior is below Lulu’s current 72-page Amazon Global Distribution minimum.
• Never infer Barnes & Noble shelf placement from Ingram availability.
• Record that Global Distribution review can take at least 12 weeks and requires creator proof approval.

Fixtures and portability

• Redistribution-safe synthetic comic fixture covering full bleed, spreads split into single pages, metadata, barcode safe area, and cover-template alignment.
• Passing and failing EPUB fixtures.
• Native Linux and Termux/proot-compatible local execution where underlying tools are available.
• Capability discovery reports missing optional tools honestly.
• Golden report/schema fixtures and reproducibility checks.
• Adapter authoring documentation shows how another printer/provider can implement the same generic publication capability.

Acceptance criteria

• A project can request Lulu candidates declaratively through the generic profile/adapter system.
• Provider-specific rules stay outside the core artifact model.
• Every candidate is traceable to source, profile, rule pack, template, adapter/tool versions, validation, and approval state.
• A valid generic PDF/EPUB that is invalid for a requested Lulu channel cannot be labeled Lulu-compliant.
• No credentials, upload side effects, ISBN allocation, proof approval, or publication occur.
• Formatting, Clippy, tests, docs, and CI pass.

Official references

• Lulu mandatory print distribution requirements
• Lulu print-book creation
• Lulu mandatory EPUB distribution requirements
• Lulu ebook publishing for Global Distribution
• Lulu ebook accessibility guidance

Dependencies

• Stabilize Transform v2 and the plugin SDK around typed artifact I/O #357 — typed artifact/plugin SDK and lifecycle hook boundary
• Add artifact validation, fidelity gates, and a capability conformance matrix #360 — validation, fidelity gates, and capability conformance
• Establish first-class adapter packs for the high-value open tool ecosystem #362 — first-class adapter-pack architecture
• Evaluate and implement EPUB and KEPUB derivative support #344 — EPUB/KEPUB derivative support
• Add a magazine publication profile and complete multi-channel release bundle #364 — generic magazine/multi-channel publication profile

The Orientation consumer is tracked in incomprisllc/comics#22. Keep its current local builder as a transitional fallback until this adapter demonstrates parity.