Organize bundled Rust resources under asset directories (#41477)

## Why

The `core` and `tui` Bazel targets treated nearly their entire crate trees as
compile-time data, mixing embedded runtime resources with source files and test
fixtures.

## What changed

- Move embedded resources for `core` and `tui` into dedicated `assets/`
  directories and update their `include_str!` paths.
- Restrict Bazel compile data to explicit asset and frame directories.
- Move test-only prompts into `tests/fixtures`, resolve the core prompt through
  `find_resource!`, and reuse the integration-test file glob when assembling
  Bazel test data.

GitOrigin-RevId: eee9b0e41df77ea2604215a7f7333a6fe8317bfa

codex-rs/core/src/session/tests.rs

@@ -1613,8 +1613,12 @@ async fn user_shell_commands_remain_login_shells_when_model_login_shells_are_dis
 
 #[tokio::test]
 async fn get_base_instructions_no_user_content() {
+    let prompt_path = codex_utils_cargo_bin::find_resource!(
+        "tests/fixtures/prompt_with_apply_patch_instructions.md"
+    )
+    .expect("resolve prompt fixture path");
     let prompt_with_apply_patch_instructions =
-        include_str!("../../prompt_with_apply_patch_instructions.md");
+        std::fs::read_to_string(prompt_path).expect("read prompt fixture");
     let models_response = bundled_models_response()
         .unwrap_or_else(|err| panic!("bundled models.json should parse: {err}"));
     let model_info_for_slug = |slug: &str, config: &Config| {