Display supported protocols in status report host section

The `host` section in `tsunagi status` previously hardcoded
`implementation: userspace WireGuard (boringtun); no kernel module needed`
and omitted information about data plane protocols supported by the build.

Changes:
- Add `protocols` row to `host_section` listing supported protocols
  and their wire versions (`wg-quic (wire v4), tcp-tls (wire v1)`) with a note
  directing to `tsunagi protocols` for detailed options.
- Update `implementation` row to reflect the multi-protocol userspace
  data plane (`userspace overlay (boringtun WireGuard, TCP TLS 1.3); no kernel module needed`).

Validation on Linux:
- `cargo fmt --all -- --check` passed.
- `cargo clippy --locked --workspace --all-targets -- -D warnings` passed.
- `cargo test --locked --workspace --all-targets` passed.

crates/tsunagi-cli/src/main.rs

@@ -2842,10 +2842,18 @@ fn host_section() -> report::Section {
     use report::{Health, Row, Section};
 
     let mut host = Section::new("host");
+    let protocols: Vec<String> = PROTOCOLS
+        .iter()
+        .map(|spec| format!("{} (wire v{})", spec.name, spec.version))
+        .collect();
+    host.push(
+        Row::new(Health::Info, "protocols", protocols.join(", "))
+            .with_note("run `tsunagi protocols` to see what each one takes"),
+    );
     host.push(Row::new(
         Health::Info,
         "implementation",
-        "userspace WireGuard (boringtun); no kernel module needed",
+        "userspace overlay (boringtun WireGuard, TCP TLS 1.3); no kernel module needed",
     ));
     {
         if cfg!(target_os = "linux") {