Keep Rust PRs green with a minimal CI gate

Add a focused GitHub Actions workflow for pull requests into main plus
manual dispatch. The workflow checks workspace formatting and runs the
rusty-claude-cli crate tests so we get a real signal on the active Rust
surface without widening scope into a full matrix.

Because the workspace was not rustfmt-clean, include the formatting-only
updates needed for the new fmt gate to pass immediately.

Constraint: Keep scope to a fast, low-noise Rust PR gate
Constraint: CI should validate formatting and rusty-claude-cli without expanding to full workspace coverage
Rejected: Full workspace test or clippy matrix | too broad for the one-hour shipping window
Rejected: Add fmt CI without reformatting the workspace | the new gate would fail on arrival
Confidence: high
Scope-risk: narrow
Directive: Keep this workflow focused unless release requirements justify broader coverage
Tested: cargo fmt --all -- --check
Tested: cargo test -p rusty-claude-cli
Tested: YAML parse of .github/workflows/rust-ci.yml via python3 + PyYAML
Not-tested: End-to-end execution on GitHub-hosted runners

rust/crates/runtime/src/mcp_client.rs

@@ -97,12 +97,10 @@ impl McpClientTransport {
             McpServerConfig::Sdk(config) => Self::Sdk(McpSdkTransport {
                 name: config.name.clone(),
             }),
-            McpServerConfig::ManagedProxy(config) => {
-                Self::ManagedProxy(McpManagedProxyTransport {
-                    url: config.url.clone(),
-                    id: config.id.clone(),
-                })
-            }
+            McpServerConfig::ManagedProxy(config) => Self::ManagedProxy(McpManagedProxyTransport {
+                url: config.url.clone(),
+                id: config.id.clone(),
+            }),
         }
     }
 }