Update rmcp to 3.5.1

[dependabot]

Updates rmcp from 3.5.0 to 3.5.1. The lockfile also resolves tempfile 3.27 through its supported getrandom 0.4.3 dependency.

The real HTTP resource-validation regression now checks HTTP 200, JSON-RPC error -32602, request ID 7 and the invalid_resource_uri denial audit. This proves the well-formed request reached Fitz's handler. Malformed transport metadata remains separately covered as HTTP 400.

The Stream comparison infrastructure was extracted and merged in #474. This PR now changes only Cargo.toml, Cargo.lock and the existing MCP boundary regression (+7/-7). Hosted qualification uses #474's fresh artifact provenance, preserved baseline dependencies and unchanged timing controls.

Validation

• Final candidate cdd90db is based on merged develop 2919201. The original published head remains an ancestor; its three-file +7/-7 patch and blobs match reviewed preparation. Merged UI, permission guidance and all comparison infrastructure are preserved.
• Fresh 83 unique MCP/HTTP/parity/disabled/stdio tests passed (93 passing executions, including the 10 boundary tests repeated inside transport; two existing provider tests ignored).
• Fresh full locked workspace passed 2,835 tests across 49 parent targets (7 ignored; unit 2,151 passed, 3 ignored). Format, diff and full locked/all-target/all-feature pedantic Clippy passed.
• Independent final adversarial review is clean at cdd90db: published package checksums/source, dependency resolution, HTTP handler/protocol error separation, preserved merged changes and the unchanged three-file patch were verified.
• Fresh exact-head CI passed backend, frontend and native AMD64/ARM64 constrained container qualification; all three CodeQL analyses passed.
• First Stream run 38163915881 passed the dependency timing comparison against 2919201 with the original rmcp 3.5.0 baseline resolution. Both complete 32-workload campaigns used the unchanged default profile and passed all eight original budgets; all four unchanged controls passed.
• Independent artifact audit accepted provenance and all 816 raw summary means (228 captures, 4,896 samples). Both library formats and all three benchmark executables differ, so equivalence was false and full timing correctly ran. Artifact 11712972207 ZIP SHA256 is 21788f51aef2517e91cae01f1645a0de4c57467c1313aee7b71b522045801d81, matching GitHub; audit JSON SHA256 is 64419142927e826266d47a560cf7d4bb939cfcc9339327869930c36cb0d6b1c7.

AI assistance: Codex refined the handler regression, extracted the independently merged infrastructure and reviewed the dependency boundary.