feat: centralize default constants and refactor overlay enter handling in TUI

apps/infrastructure/src/workflow/engine/primitives.rs

@@ -41,7 +41,7 @@ pub async fn execute_primitive(directive: &str, tool_ctx: &ToolCtx) -> Result<St
         .providers
         .get(&provider)
         .map(|p| p.api_base.clone())
-        .unwrap_or_else(|| "https://opencode.ai/zen/v1".to_string());
+        .unwrap_or_else(|| zesdex_domain::agent::defaults::DEFAULT_API_BASE.to_string());
 
     let api_key = crate::llm::provider::resolve_api_key(&settings, &app_config);
 

apps/infrastructure/src/workflow/hive_mind/cycle.rs

@@ -50,7 +50,7 @@ pub async fn execute_cycle(
         .providers
         .get(&provider)
         .map(|p| p.api_base.clone())
-        .unwrap_or_else(|| "https://opencode.ai/zen/v1".to_string());
+        .unwrap_or_else(|| zesdex_domain::agent::defaults::DEFAULT_API_BASE.to_string());
 
     let api_key = crate::llm::provider::resolve_api_key(&settings, &app_config);