Public API docs + v1.0 release

[JakeMG-INL]

What to build

Document EXPy's v1.0 public API surface and ship v1.0 as a pip-installable Python package. Rewrite the README to cover the full surface declared in ADR-0013 (packaging) and ADR-0014 (surface refinements): the eight Namespace members, the six-method EXIProcessor API (feature-gated via hasattr), the eight *Processor CLI binaries (each with six modes where supported), the public expy.v2gjson constructors, the typed EncodeError/DecodeError attribute contract, and the per-Namespace top-level envelope split. Add a CHANGELOG.md entry for v1.0 enumerating the surface. Tag v1.0 on main.

References: ADR-0013 (packaging), ADR-0014 (surface refinements). ADR-0003 and ADR-0012 are historical and superseded for v1.0 by these two.

Acceptance criteria

• pyproject.toml ships an installable expy package (scikit-build-core or equivalent); pip install . in a fresh venv produces a working installation with the eight per-Namespace .so files bundled as package data
• Public import paths are from expy import EXIProcessor, Namespace and from expy.v2gjson import sap, din, iso2, iso20_common, iso20_ac, iso20_dc, iso20_wpt, iso20_acdp
• Namespace (renamed from ProtocolEnum) is documented with all eight members: SAP, DIN, ISO2, ISO20_COMMON, ISO20_AC, ISO20_DC, ISO20_WPT, ISO20_ACDP; EXIProcessor.__init__ takes namespace: Namespace
• README documents the six-method EXIProcessor API (encode / decode for Document / Fragment / XmldsigFragment roots) and the hasattr-based feature-detection idiom for Fragment / XmldsigFragment on SAP and DIN
• README documents the eight *Processor CLI binaries and their six modes (--encode, --decode, --encode-fragment, --decode-fragment, --encode-xmldsig, --decode-xmldsig), with the feature-gated subset on SAP and DIN absent from --help
• README documents expy.v2gjson as public, with a naming-conventions note that identifiers mirror libcbv2g verbatim (non-PEP-8 casing such as costKindType, RelativeTimeIntervalType, EVSE_NotReady) and a pointer to per-file ruff N801,N802,N806 suppressions for strict-linting consumers
• README documents the typed exception attribute contract: EncodeError and DecodeError carry rc: int, namespace: str, root: Literal["exiDocument", "exiFragment", "xmldsigFragment"]; str(e) remains informational
• README documents the EVerest JSON shape ({"bytes": [...], "bytesLen": N}, "isUsed": true) and the per-Namespace top-level envelope split: DIN and ISO-2 use V2G_Message(Header=..., Body=...); SAP and the five ISO-20 Namespaces use raw {"<MessageName>": ...} or {"Body": {"<MessageName>": ...}}
• CHANGELOG.md exists with a v1.0 entry enumerating the surface above
• All Processor round-trip integration test suites pass on main
• v1.0 git tag created on main
• Human approval received before closing the issue

Blocked by

• Fragment + XmldsigFragment API, regenerate ISO-2 #2, Eight-namespace ProtocolEnum split + ISO20_COMMON end-to-end #3, ISO20_AC end-to-end #4, ISO20_DC end-to-end #5, ISO20_WPT end-to-end #6, ISO20_ACDP end-to-end #7

[JakeMG-INL]

The pre-1.0 audit grill session split this issue into seven blocking work items. README rewrite, CHANGELOG, and v1.0 tag (the original scope of #8) should land after the public surface is in shape.

Blockers:

• Remove stale include/ headers and root-level scratch files #27 — Remove stale include/ headers and root-level scratch files
• Rename V2Gjson/apphand.py to V2Gjson/sap.py #28 — Rename V2Gjson/apphand.py → V2Gjson/sap.py
• Expose __version__ from a single _version.py #29 — Expose __version__ from a single _version.py
• CLI exec parity: build a binary for each ISO-20 Namespace #30 — CLI exec parity: build a binary for each ISO-20 Namespace
• Extend v2gjson_emitter to emit constructor functions #31 — Extend v2gjson_emitter to emit constructor functions
• Migrate all 8 V2Gjson modules to codegen and adopt module-as-namespace __init__.py #32 — Migrate all 8 V2Gjson modules to codegen and adopt module-as-namespace __init__.py
• Cross-namespace parity tests and V2Gjson roundtrip suite #33 — Cross-namespace parity tests and V2Gjson roundtrip suite

Public-surface decisions made during the grill are recorded in ADR-0012 (supersedes ADR-0003): three public surfaces for v1.0 — Python EXIProcessor, V2Gjson builder package, and per-Namespace CLI binaries. Generated C++ headers remain internal. CONTEXT.md updated to declare V2Gjson builder as a domain term.