fix: some nit Rust reference issues (#3849)

Fix some small references issue. No behavioural change. Just making the
code cleaner

codex-rs/core/src/client_common.rs

@@ -34,13 +34,11 @@ pub struct Prompt {
 }
 
 impl Prompt {
-    pub(crate) fn get_full_instructions(&self, model: &ModelFamily) -> Cow<'_, str> {
+    pub(crate) fn get_full_instructions<'a>(&'a self, model: &'a ModelFamily) -> Cow<'a, str> {
         let base = self
             .base_instructions_override
             .as_deref()
             .unwrap_or(model.base_instructions.deref());
-        let mut sections: Vec<&str> = vec![base];
-
         // When there are no custom instructions, add apply_patch_tool_instructions if:
         // - the model needs special instructions (4.1)
         // AND
@@ -54,9 +52,10 @@ impl Prompt {
             && model.needs_special_apply_patch_instructions
             && !is_apply_patch_tool_present
         {
-            sections.push(APPLY_PATCH_TOOL_INSTRUCTIONS);
+            Cow::Owned(format!("{base}\n{APPLY_PATCH_TOOL_INSTRUCTIONS}"))
+        } else {
+            Cow::Borrowed(base)
         }
-        Cow::Owned(sections.join("\n"))
     }
 
     pub(crate) fn get_formatted_input(&self) -> Vec<ResponseItem> {

codex-rs/core/src/openai_tools.rs

@@ -333,7 +333,7 @@ pub(crate) struct ApplyPatchToolArgs {
 /// Responses API:
 /// https://platform.openai.com/docs/guides/function-calling?api-mode=responses
 pub fn create_tools_json_for_responses_api(
-    tools: &Vec<OpenAiTool>,
+    tools: &[OpenAiTool],
 ) -> crate::error::Result<Vec<serde_json::Value>> {
     let mut tools_json = Vec::new();
 
@@ -348,7 +348,7 @@ pub fn create_tools_json_for_responses_api(
 /// Chat Completions API:
 /// https://platform.openai.com/docs/guides/function-calling?api-mode=chat
 pub(crate) fn create_tools_json_for_chat_completions_api(
-    tools: &Vec<OpenAiTool>,
+    tools: &[OpenAiTool],
 ) -> crate::error::Result<Vec<serde_json::Value>> {
     // We start with the JSON for the Responses API and than rewrite it to match
     // the chat completions tool call format.

codex-rs/core/src/shell.rs

@@ -32,15 +32,19 @@ pub enum Shell {
 impl Shell {
     pub fn format_default_shell_invocation(&self, command: Vec<String>) -> Option<Vec<String>> {
         match self {
-            Shell::Zsh(zsh) => {
-                format_shell_invocation_with_rc(&command, &zsh.shell_path, &zsh.zshrc_path)
-            }
-            Shell::Bash(bash) => {
-                format_shell_invocation_with_rc(&command, &bash.shell_path, &bash.bashrc_path)
-            }
+            Shell::Zsh(zsh) => format_shell_invocation_with_rc(
+                command.as_slice(),
+                &zsh.shell_path,
+                &zsh.zshrc_path,
+            ),
+            Shell::Bash(bash) => format_shell_invocation_with_rc(
+                command.as_slice(),
+                &bash.shell_path,
+                &bash.bashrc_path,
+            ),
             Shell::PowerShell(ps) => {
                 // If model generated a bash command, prefer a detected bash fallback
-                if let Some(script) = strip_bash_lc(&command) {
+                if let Some(script) = strip_bash_lc(command.as_slice()) {
                     return match &ps.bash_exe_fallback {
                         Some(bash) => Some(vec![
                             bash.to_string_lossy().to_string(),
@@ -102,7 +106,7 @@ impl Shell {
 }
 
 fn format_shell_invocation_with_rc(
-    command: &Vec<String>,
+    command: &[String],
     shell_path: &str,
     rc_path: &str,
 ) -> Option<Vec<String>> {
@@ -118,8 +122,8 @@ fn format_shell_invocation_with_rc(
     Some(vec![shell_path.to_string(), "-lc".to_string(), rc_command])
 }
 
-fn strip_bash_lc(command: &Vec<String>) -> Option<String> {
-    match command.as_slice() {
+fn strip_bash_lc(command: &[String]) -> Option<String> {
+    match command {
         // exactly three items
         [first, second, third]
             // first two must be "bash", "-lc"