release(windows): enforce Store and direct-EXE delivery contract

[Qiyuanqiii]

Summary

Implements the repository-owned portion of #123's Windows two-deliverable contract:

• the sole direct user entry is zero-argument TraverseBoard.exe;
• the Store route produces an identity-bound MSIX/MSIXUPLOAD for Partner Center;
• the old Start-Prayu-Operator-Preview.cmd is removed with no renamed Start wrapper;
• internal ZIP/development MSIX/Store upload/evidence sidecars remain validation material, not extra products.

Part of #37. Refs #123. This PR stays Draft and intentionally does not close #123 until a real stable candidate passes the external gates below.

Repository-owned implementation

• Added a two-phase protected direct-EXE signing contract:
  • prepare emits an exact payload-bound signing request;
  • finalize consumes the unchanged request, signed EXE, and retained handoff;
  • every stable verifier requires the repository-configured signer Subject/thumbprint and never self-anchors from evidence;
  • PE normalization proves signing changed only permitted Authenticode regions;
  • PKCS#7 parsing independently requires SHA-256 Authenticode file/signature digests, exactly one RFC 3161 timestamp, SHA-256 timestamp imprint, matching message imprint, and the token's real genTime;
  • stable request/handoff/evidence are published as hash-bound sidecars, while intake-only TraverseBoard-signed.exe is removed.
• Added permission-scoped GitHub provenance/SBOM attestations for the public EXE and Store upload, with downloadable bundles, exact subject/predicate checks, and offline gh attestation verify.
• Reworked Store packaging/verification around msix_manifest.v2: exact Partner Center identity/version/architecture, deterministic one-entry .msixupload, immutable release-evidence inventory, and pre-sign Store payload to post-sign public-EXE binding.
• Added finalize-windows-release.ps1. It emits immutable windows_release_completion.v1 only after live verification of:
  • an installed package with exact identity/version/architecture/payload and SignatureKind=Store;
  • Partner Center/listing/privacy/age readbacks;
  • the published GitHub tag, body, exact asset allowlist, hashes, and attestation bundles;
  • four hash-resolved Windows 10/11 × 100%/200% DPI × zh-CN IME lifecycle rows, including upgrade, downgrade rejection, repair, uninstall/reinstall, and data-sentinel preservation.
• Explicitly labels Partner Center exports, screenshots, and operator lifecycle reports as reviewer-attested/hash-bound evidence rather than cryptographic proof.
• Added canonical bilingual release notes and exact public asset inventory. New releases contain neither the old CMD nor a renamed Start helper.
• Registered all new durable protocols and added release/workflow contract tests.

Validation performed

• Real clean reproducible Windows build: two TraverseBoard.exe builds matched byte-for-byte.
• Web: 73 test files / 351 tests passed; production bundle built.
• Internal ZIP: deterministic double-pack and exact-entry verification passed.
• Real MakeAppx development MSIX and synthetic non-submittable Store MSIX/MSIXUPLOAD: pack, unpack, identity/architecture/payload/evidence inspection passed.
• Prerelease direct-EXE and portable verification passed in PowerShell 7 and Windows PowerShell 5.1.
• The stable cryptographic profile was exercised against valid embedded Authenticode/RFC 3161 files in both PowerShell versions, including SHA-256 file digest and timestamp message-imprint parsing.
• go test -count=1 ./cmd/releasegate ./internal/releasegate ./internal/protocolregistry ./internal/producte2e ./internal/packagede2e passed.
• actionlint v1.7.12, both PowerShell parsers, protocol-registry synchronization, and git diff --check passed.

A repository-wide local go test ./... run also exposed an unrelated existing Windows deadline assertion in internal/application; the concurrent internal/store timeout passed when rerun alone. No implementation file in either failing path is changed here; GitHub CI remains authoritative for the new revision.

External completion gates (not claimed by this PR)

• configure the real six repository values: Partner Center Name/Publisher/PublisherDisplayName/version and the approved direct signer Subject/thumbprint;
• have the protected public code-signing service sign the exact request and return its non-secret handoff;
• upload the exact .msixupload, obtain runFullTrust approval, certification, Microsoft Store signing, listing/privacy/age publication, and live installed-package readback;
• collect the four real Windows lifecycle rows and same-candidate test(security): execute Standard Code attack and recovery matrix #181/test(product): validate packaged four-language loop and delivery UX #182 product/security evidence.

Until those facts exist, final completion fails closed and #123 remains open.