fix: update rmcp SDK with shadow channel fix + minor fixes

- Update rmcp to latest commit with comprehensive SSE shadow channel
  tests (15 tests covering reconnect, dead primary replacement,
  notification routing, resume paths, and edge cases)
- Add last-event-id to non-redacted headers in logging middleware
- Fix missing granted_scopes field in credential_store test initializers

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Signed-off-by: Mohammod Al Amin Ashik <maa.ashik00@gmail.com>

Author: its-mash

Cargo.lock

@@ -587,6 +587,7 @@ mod tests {
         let credentials = StoredCredentials {
             client_id: "new-client-id".to_string(),
             token_response: Some(token_response),
+            granted_scopes: Vec::new(),
         };
 
         store.save(credentials).await.unwrap();
@@ -644,6 +645,7 @@ mod tests {
         let credentials = StoredCredentials {
             client_id: "client-id".to_string(),
             token_response: Some(token_response),
+            granted_scopes: Vec::new(),
         };
 
         store.save(credentials).await.unwrap();

crates/mcpmux-gateway/src/pool/credential_store.rs

@@ -45,6 +45,7 @@ fn redact_headers_compact(headers: &axum::http::HeaderMap) -> String {
                     | "user-agent"
                     | "mcp-session-id"
                     | "mcp-protocol-version"
+                    | "last-event-id"
             )
         })
         .map(|(name, value)| {