fix(mcp): work with protocol 2026-07-28 clients (2.3.2)

[mrramdn]

Why

Claude Code 2.1.296 connects to MCP servers with protocol 2026-07-28. It skips initialize and sends server/discover with _meta["io.modelcontextprotocol/protocolVersion"] = "2026-07-28". Laci 2.3.1 lists that version in supportedVersions, but its tools/list result then has no ttlMs or cacheScope, which 2026-07-28 requires on list results (SEP-2549). Claude Code rejects the list, so Laci's tools are missing:

Status: ! Connected · tools fetch failed
Issue: Invalid result for tools/list: [ { "expected": "number", "code": "invalid_type", "path": [ "ttlMs" ], "message": "Invalid input: expected number, received undefined" }, { "code": "invalid_value", "values": [ "public", "private" ], "path": [ "cacheScope" ], "message": "Invalid option: expected one of \"public\"|\"private\"" } ]

Cause

rmcp 3.5.0 added the hints only to results built by its #[tool_handler] and #[prompt_handler] macros. Laci implements list_tools itself (ListToolsResult::with_all_items), so the fields stayed empty and were left out of the JSON.

What changes

• rmcp 3.5.0 → 3.5.1, with rmcp-macros, in Cargo.lock only. 3.5.1 fills in missing hints for every 2026-07-28 peer (rust-sdk#1308): ttlMs: 0 and cacheScope: "private", so clients never cache the list. Sessions that start with initialize keep the old shape. mcp.rs is unchanged.
• MCP smoke check: a second laci mcp is spoken to with 2026-07-28. server/discover must list 2026-07-28, and tools/list with the same _meta must return the 15 tools with a numeric ttlMs and a cacheScope of public or private. 28 → 30 checks. Starting and stopping the server moved into start() and stop(); the existing checks are unchanged.
• 2.3.2: version in Cargo.toml, Cargo.lock, package.json, ui/package.json and tauri.conf.json, the changelog entry, and the README status line, which still said 2.1.0.

Checks

• cargo fmt --all -- --check, strict Clippy and cargo test --workspace --features custom-protocol: 180 passed, 1 ignored.
• UI typecheck, lint and build; node scripts/ui-state-smoke.mjs.
• node scripts/mcp-smoke.mjs target/debug/laci: MCP smoke passed: 15 tools, 30 checks, …. Against 2.3.1 the new check fails with tools/list must carry ttlMs for 2026-07-28 clients.
• tools/list keys for a 2026-07-28 request: 2.3.1 ["resultType","tools"], this branch ["resultType","ttlMs","cacheScope","tools"] (ttlMs: 0, cacheScope: "private"). A session started with initialize at 2025-11-25 still gets ["tools"].
• Claude Code 2.1.296: claude mcp add --scope local <name> -e LACI_HOME=<empty dir> -- <binary> mcp, then claude mcp get <name>:
  • 2.3.1 (~/.local/bin/laci): Status: ! Connected · tools fetch failed, with the issue above
  • this branch (target/debug/laci): Status: ✔ Connected

After merge

v2.3.2 is tagged and the release is published.