tui: replace debug/test-only crate features with debug_assertions

## Why

The remaining `vt100-tests` and `debug-logs` features in `codex-tui` were only selecting debug and test-only behavior. Those are exactly the cases where this repo already accepts `#[cfg(debug_assertions)]` as the Cargo-free substitute.

## What changed

- delete `vt100-tests` and `debug-logs` from `codex-tui`
- gate the VT100 integration tests with `debug_assertions` instead of a Cargo feature
- gate the textarea debug log site with `debug_assertions`
- shrink the manifest verifier allowlist again so only the remaining real feature exceptions stay permitted

.github/scripts/verify_cargo_workspace_manifests.py

@@ -32,8 +32,6 @@ MANIFEST_FEATURE_EXCEPTIONS = {
     },
     "codex-rs/tui/Cargo.toml": {
         "default": ("voice-input",),
-        "vt100-tests": (),
-        "debug-logs": (),
         "voice-input": ("dep:cpal",),
     },
 }

codex-rs/tui/Cargo.toml

@@ -19,10 +19,6 @@ path = "src/lib.rs"
 
 [features]
 default = ["voice-input"]
-# Enable vt100-based tests (emulator) when running with `--features vt100-tests`.
-vt100-tests = []
-# Gate verbose debug logging inside the TUI implementation.
-debug-logs = []
 voice-input = ["dep:cpal"]
 
 [lints]

codex-rs/tui/src/bottom_pane/textarea.rs

@@ -530,7 +530,7 @@ impl TextArea {
                 self.move_cursor_to_end_of_line(/*move_down_at_eol*/ true);
             }
             _o => {
-                #[cfg(feature = "debug-logs")]
+                #[cfg(debug_assertions)]
                 tracing::debug!("Unhandled key event in TextArea: {:?}", _o);
             }
         }

codex-rs/tui/tests/all.rs

@@ -1,6 +1,6 @@
 // Single integration test binary that aggregates all test modules.
 // The submodules live in `tests/suite/`.
-#[cfg(feature = "vt100-tests")]
+#[cfg(debug_assertions)]
 mod test_backend;
 
 #[allow(unused_imports)]

codex-rs/tui/tests/suite/vt100_history.rs

@@ -1,4 +1,4 @@
-#![cfg(feature = "vt100-tests")]
+#![cfg(debug_assertions)]
 #![expect(clippy::expect_used)]
 
 use crate::test_backend::VT100Backend;

codex-rs/tui/tests/suite/vt100_live_commit.rs

@@ -1,4 +1,4 @@
-#![cfg(feature = "vt100-tests")]
+#![cfg(debug_assertions)]
 
 use crate::test_backend::VT100Backend;
 use ratatui::layout::Rect;