Absorb UBL/XSD sources into `novolis-xsd`

name: Novolis XSD UBL absorb overview: Create a new Novolis-Platform library repo novolis-xsd that absorbs the Frank UBL/XSD lineage into a general XSD→C# generator plus pre-generated UBL and Peppol packages (SBDH lives under Peppol, not a separate facet)—reversing the current governance “skip finance/UBL” stance. todos:

• id: gov-reverse-skip

content: Update governance skip/import/naming docs for novolis-xsd finance/UBL decision status: completed

• id: bootstrap-repo

content: Create Novolis-Platform/novolis-xsd from template under d:\novolis\novolis-xsd status: completed

• id: port-generator

content: Port Frank.UblSharp Generation pipeline into Novolis.Xsd.Generator + tools/XsdGen status: completed

• id: pregen-ubl

content: Vendor UBL 2.1 XSDs, generate Novolis.Xsd.Ubl + Validation, publish to GPR status: completed

• id: peppol-phase

content: Port SBDH into Novolis.Xsd.Peppol with BIS schemas, wrap/unwrap helpers, and tests status: completed

• id: helpers-perf

content: Ship serializer cache/stream helpers + performance tests; dogfood if needed status: completed isProject: false

Verdict

Stand up one new library repo `novolis-xsd` (from `novolis-template-dotnet`). Primary technical lineage is [Frank.UblSharp](https://github.com/frankhaugen/Frank.UblSharp) (supported Roslyn + XmlSchemaClassGenerator pipeline). Other repos become migration inputs, test oracles, or historical credit—not parallel generators.

Peppol owns the envelope: SBDH is not a separate package. Types and wrap/unwrap helpers from Frank.Libraries.SBDH land under `Novolis.Xsd.Peppol` alongside BIS schemas/helpers. Prefer Peppol naming in public APIs; keep Sbdh only as internal type names where the OASIS/CEFACT vocabulary requires it.

This does not touch novolis-markup / Manuscript (different “document” domain). It does reverse entries in `frank-repos-explicit-skip.md` and `frank-codegen-devtools.md`.

Source disposition

Dependency on `XmlSchemaClassGenerator` (nuget.org) stays explicit—same engine Frank.UblSharp and Finance.Documents already wrap—rather than inventing a third generator.

Target shape

d:\novolis\novolis-xsd\
  schemas\ubl-2.1\          # vendored OASIS XSDs (or submodule) used by generate tool
  schemas\peppol\           # BIS XSDs + SBDH/envelope schemas used by Peppol package
  tools\XsdGen\             # CLI that writes Generated/ into packages
  src\Novolis.Xsd\                  # options, emit model, shared XML helpers
  src\Novolis.Xsd.Generator\        # library API (schema set → C# sources)
  src\Novolis.Xsd.Tool\             # packable dotnet tool (arbitrary XSD)
  src\Novolis.Xsd.Ubl\              # pre-generated UBL 2.1 + serialize helpers
  src\Novolis.Xsd.Ubl.Validation\   # schema validate
  src\Novolis.Xsd.Peppol\           # SBDH envelope + Peppol BIS + wrap/process helpers
  tests\Novolis.Xsd.Unit\
  Novolis.Xsd.slnx

Orthogonal library island (like markup/storage): Avalonia-free, not on the Math→Physics spine. Pack 2026.1.* to GitHub Packages; NuGet-only restore.

flowchart LR
  xsdFiles[XSD schemas] --> genLib[Novolis.Xsd.Generator]
  genLib --> tool[Novolis.Xsd.Tool]
  tool --> ublPkg[Novolis.Xsd.Ubl Generated]
  tool --> peppolPkg[Novolis.Xsd.Peppol]
  sbdhPort[Frank.Libraries.SBDH port] --> peppolPkg
  ublPkg --> helpers[Serialize validate pool helpers]
  peppolPkg --> helpers

Generation product decisions (locked)

1. Pre-generated packages for consumers — CI/tools/XsdGen writes C# into src/Novolis.Xsd.Ubl/Generated/ (and Peppol). Consumers do not pay source-generator cost on every build. The Frank.UblSharp in-process Roslyn generator becomes the engine inside Novolis.Xsd.Generator / tool, not the default UBL package shipping mode.
2. XmlSerializer-first models — emit partial class (+ enums) with Xml* attributes (UblSharp / ubllarsen fidelity). Optional record projections or --emit records come later for non-XML DTOs; records are a poor default for full UBL XmlSerializer fidelity.
3. Namespaces — Novolis.Xsd.Ubl.{DocumentName} (and common CAC/CBC namespaces), inspired by Finance.Documents’ per-document split, not one giant root namespace. Peppol: Novolis.Xsd.Peppol.* (envelope + BIS).
4. General XSD path — same generator accepts arbitrary schema sets (Peppol, custom profiles) via tool flags: root namespace, naming scheme, collection type, nullable annotations.
5. Licensing — MIT for Novolis packages; retain NOTICE for UblSharp/OASIS schema terms and ubllarsen ancestry; do not copy Unlicense sources wholesale if regenerated under MIT tooling.
6. One Peppol facet — no separate SBDH package or schemas/sbdh/ tree; envelope schemas live under schemas/peppol/.

Performant helpers (ship with `Novolis.Xsd` / `Novolis.Xsd.Ubl` / `Novolis.Xsd.Peppol`)

Port and harden patterns from UblSharp + Finance.Documents:

• Cached XmlSerializer / typed document facade (à la UblDocument)
• Serialize/deserialize to stream, UTF-8 bytes, and XmlReader/XmlWriter without intermediate strings
• Schema validation API from Frank.UblSharp.Validation
• Peppol envelope wrap/unwrap around UBL payloads (from SBDH port) without full DOM where practical
• Optional later: HTML/text render from Finance.Documents.Renderer (dogfood or separate facet—not phase 1)

Phased delivery

Phase 0 — Governance + repo bootstrap

• Update skip/import docs: Finance UBL and XsdCodeGeneration move from “skip/spike” to “import into novolis-xsd”.
• Add row to `frank-naming-and-structure.md`.
• Create Novolis-Platform/novolis-xsd from template; clone under d:\novolis\novolis-xsd.
• Wire into Platform slnx map when first packable projects exist (Generate-Platform-Slnx.ps1).

Phase 1 — Generator spine

• Port Frank.UblSharp Generation + schema-set loading/XmlSchemaMetaVisitor/UblGeneratorFactory into Novolis.Xsd.Generator (Novolis naming, net10.0, TUnit).
• Replace LINQPad Generate.linq with tools/XsdGen calling the library.
• Golden tests: generate Invoice (+ one CAC type) and compare serialization round-trip against OASIS samples / existing Frank tests.

Phase 2 — Pre-generated UBL + validation

• Vendor UBL 2.1 XSDs under schemas/ubl-2.1.
• Generate full model set into Novolis.Xsd.Ubl.
• Port validation package; publish both to GPR.
• Smoke: deserialize OASIS invoice sample, validate, re-serialize.

Phase 3 — Peppol (includes SBDH)

• Port Frank.Libraries.SBDH into Novolis.Xsd.Peppol (envelope types + service helpers under Peppol namespaces).
• Add Peppol BIS Billing (and agreed message set) XSDs under schemas/peppol; generate Peppol-specific bits as needed.
• Integration test: wrap UBL Invoice in Peppol/SBDH envelope and round-trip; helpers for common Peppol identifiers / process IDs.
• Schematron stays out-of-scope unless separately approved.

Phase 4 — Polish + retire Frank lanes

• Performance tests (serializer cache, large catalogues).
• Dogfood app under novolis-dogfooding if needed (not library apps/).
• Archive or mark Frank.UblSharp / Finance.Documents.Ubl as superseded; leave XsdCodeGeneration archived.

Explicit non-goals (v1)

• No Avalonia UI / invoice designer in the library repo
• No bulk import of Frank.Libraries monolith
• No separate Novolis.Xsd.Sbdh package (SBDH is Peppol)
• No local NuGet folder feeds; no cross-repo ProjectReference in committed csproj
• No folding XSD into novolis-codegen (keeps CodeGen focused on Reflection/bindings; XSD stays domain-adjacent to UBL/Peppol)

Success criteria

• dotnet tool can generate C# from a complex multi-file XSD set (UBL-scale) into a chosen namespace
• Novolis.Xsd.Ubl + .Validation + .Peppol restore from nuget.org + GitHub Packages only and pass round-trip + validate + envelope wrap tests
• Governance skip lists and naming map agree with the new repo
• verify-nuget-only / project-ref mode scripts remain green for the new packages when added to the platform map