[DamianReeves]

Start the F# compile implementation with its portable conformance foundation. Production compiler binding and the compile command remain in the following tasks.

This change adds:

• The frontend PRD and epic [EPIC] F# source frontend and morphir compile steel thread #499 tracking, with pinned MEP/out-directory fixtures and SHA-256 provenance tests.
• A hand-authored frontend-fsharp seed covering a mutable-binding refusal across IR versions 1–4 and all three source input kinds.
• Morphir.Conformance: the official Gherkin reader, closed vocabulary and tag validation, complete matrices with explained exclusions, and independent observation comparison.
• A library adapter that receives input without expectations. Typed operational failures retain partial diagnostics, and later cases still run.
• Deterministic JSON reports with case-set digest, actual runner version, implementation identity, complete requests, stable diagnostic fields and exact model text, including invalid payloads.
• Native AOT and negative-control tests. The generic JSON comparison is a seed primitive; production model-family normalization, schema and behavioral qualification remain task 3.8.

The branch includes the plan merged in #495 and the current main guidance from #501. Existing IR models, production command behavior and compiler/Core pins are unchanged. Gherkin 35.0.0 is already used transitively by Reqnroll; the central pin promotes the same version in existing lock files.

Validation:

• Full Release test target passed, including package checks, in 5m27s after the Windows checkout fix.
• Focused project: 28/28 tests passed. Tests were observed failing before their implementing changes.
• AltCover: 94.39% sequence and 73.13% branch coverage for Morphir.Conformance, with no handwritten code excluded.
• Native osx-arm64 smoke ran all twelve variants against an intentionally incorrect adapter and emitted an unqualified JSON report. Its expanded AOT/trim warning details are a subset of the existing CLI baseline; existing FSharp.Core warnings remain visible.
• Repository lint target completed; explicit Fantomas checks passed for every new F# file. The lint target retains its existing unsupported-F# formatter messages.
• Both OpenSpec changes validate strictly, relative links resolve, whitespace checks pass and the new agent-skill sync check passes.

An earlier local full run hit the machine-home tripwire when a Rust CLI log appeared outside the test sandboxes. No test-isolation rule was weakened; the final full run passed.

OpenSpec progress is 4/53 tasks. This PR completes the tracking, fixture and MCK seed tasks; the match-reconstruction proof is already on main. Next are compile acceptance scenarios and native compilation contracts/builders/writers, followed by the in-process F# frontend.

Refs #499

Windows CI follow-up: preserve pinned upstream bytes under autocrlf, accept LF/CRLF manifests, and keep case-set bytes LF-stable. The regression failed before the fix; a disposable Git checkout with core.autocrlf=true now preserves every pinned hash and case artifact.