feat(ai): unify model discovery and effort handling

crates/dbx-core/src/cloud_sync.rs

@@ -1091,6 +1091,7 @@ mod tests {
                 proxy_url: String::new(),
                 enable_thinking: true,
                 reasoning_level: crate::ai::AiReasoningLevel::Default,
+                runtime_effort: None,
                 context_window: None,
                 codex_cli_path: None,
                 codex_cli_env: Default::default(),