fix: tui launch latency by disabling osc probe

- Codex CLI startup slowed to ~1.5 s in Terminal and Ghostty.
- This was because because Tui::new requested the terminal’s
  256-color palette via OSC 4. Trace logging showed the constructor
  waiting for 1.5s at query_terminal_palette before timing out,
  since many modern GPU terminals ignore OSC 4/10/11.
- This is a minimal change that disables those probes, but keeps it
  easy to bring the back for specific terminals that support it
  like iTerm or xterm, or with different more performant approach.

codex-rs/tui/src/terminal_palette.rs

@@ -34,6 +34,8 @@ mod imp {
     use std::sync::Mutex;
     use std::sync::OnceLock;
 
+    const TERMINAL_QUERIES_ENABLED: bool = false;
+
     struct Cache<T> {
         attempted: bool,
         value: Option<T>,
@@ -70,6 +72,9 @@ mod imp {
     }
 
     pub(super) fn terminal_palette() -> Option<[(u8, u8, u8); 256]> {
+        if !TERMINAL_QUERIES_ENABLED {
+            return None;
+        }
         static CACHE: OnceLock<Option<[(u8, u8, u8); 256]>> = OnceLock::new();
         *CACHE.get_or_init(|| match query_terminal_palette() {
             Ok(Some(palette)) => Some(palette),
@@ -78,12 +83,18 @@ mod imp {
     }
 
     pub(super) fn default_colors() -> Option<DefaultColors> {
+        if !TERMINAL_QUERIES_ENABLED {
+            return None;
+        }
         let cache = default_colors_cache();
         let mut cache = cache.lock().ok()?;
         cache.get_or_init_with(|| query_default_colors().unwrap_or_default())
     }
 
     pub(super) fn requery_default_colors() {
+        if !TERMINAL_QUERIES_ENABLED {
+            return;
+        }
         if let Ok(mut cache) = default_colors_cache().lock() {
             cache.refresh_with(|| query_default_colors().unwrap_or_default());
         }