style(agents): apply rustfmt to MCP registration paths

[Fluzko]

What does this PR do?

Check formatting has been failing on main since the per-agent MCP config path change landed (#274, commit fcb85fd). This runs rustfmt over the two files it left unformatted, unblocking that job for every open PR that has merged or rebased onto main.

Reformatting only: match-arm braces and one closure in src/agents/mod.rs, one method chain in src/agents/mcp_server_registration.rs. No behavior, signature, or control-flow change.

Verification

Ran the CI workflow's commands:

Job	Command
Check compilation	cargo check
Check formatting	cargo fmt -- --check
Run xtask checks	cargo xtask md-orphan-check
Run tests	echo 'test-agents = []' > test-agents.toml && cargo test

Disclosure questions

AI disclosure.

• The AI tool authored large parts of the code