Reuse MCP connections across runtime refreshes (#34952)

## Why

Refreshing MCP runtime state should not restart an unchanged, ready server or
relist its tools.

## What changed

- Reconcile refreshed MCP configuration against the published connection set
  and reuse connections whose transport, environment, authentication, OAuth
  credentials, and client capabilities are unchanged.
- Keep tool filters, timeouts, metadata, and plugin provenance in the published
  server view so those settings can change without reconnecting.
- Update elicitation authority in place for reused connections, and reconnect
  when connection-defining inputs or live OAuth credentials change.

## Testing

Added coverage for unchanged-server reuse, view-only and elicitation-policy
updates, connection identity changes, OAuth credential changes, and avoiding
redundant tool listing.

GitOrigin-RevId: f04f5db5fbdde127b6a14f6aa9673112c0b557e7

codex-rs/codex-mcp/src/binding_tests.rs

@@ -26,7 +26,6 @@ use crate::connection_manager::McpConnectionSet;
 use crate::rmcp_client::ManagedClient;
 use crate::server::McpServerMetadata;
 use crate::server::McpServerOrigin;
-use crate::tools::ToolFilter;
 use crate::tools::ToolInfo;
 
 const SERVER_NAME: &str = "docs";
@@ -88,7 +87,6 @@ async fn test_step(
             website_url: None,
         },
         tools: vec![tool.clone()],
-        tool_filter: ToolFilter::default(),
         tool_timeout: None,
         server_instructions: None,
         server_supports_sandbox_state_meta_capability: supports_sandbox_state_meta,