fix(connect): handle v1 GraphService format and B5 digests for buf 1.69.0

[onokonem]

Summary

Fixes buf dep update crash when using the proxy with buf 1.69.0+.

Buf 1.69.0 uses DigestTypeB5 as the default, which routes module API calls through v1 paths instead of v1beta1. The proxy had three issues handling v1 requests, causing a nil pointer crash, invalid UTF-8 errors, and digest verification failures.

Changes

Request format fix

ServeGraph used the v1beta1 request parser for all paths. v1 GetGraphRequest uses ResourceRef directly in field 1, while v1beta1 wraps each in GetGraphRequest_ResourceRef { ResourceRef, Registry }. Added parseGetGraphResourceRefsV1 and path-based parser selection.

Key files: internal/connect/commits_helpers.go, internal/connect/commits.go

Response format fix

v1 Graph.commits expects repeated Commit directly (no wrapper), while v1beta1 uses Graph_Commit { Commit, Registry }. Added conditional response format based on path.

Key files: internal/connect/commits.go

B5 digest computation

The v1 DigestType enum has no B4 type (only DIGEST_TYPE_B5 = 1). B5 wraps the B4 hash differently: SHA3-Shake256("shake256:" + hex(b4_hash)). Added toB5Digest() helper applied to all v1 handler paths.

Key files: internal/connect/commits.go

Verification

• Existing unit tests pass
• buf dep update in cyp-hardware-manager/api/proto exits with code 0
• Generated buf.lock contains all 4 deps with correct B5 digests

Key Decisions

• v1 and v1beta1 API paths both remain registered for backward compatibility
• B5 digest computation assumes zero dependencies per module (matches proxy's single-module design)