[codex] Remove unused legacy shell tools (#22246)

## Why

Recent session history showed no active use of the raw `shell`,
`local_shell`, or `container.exec` execution surfaces. Keeping those
handlers/specs wired into core leaves duplicate shell execution paths
alongside the supported `shell_command` and unified exec tools.

## What changed

- Removed the raw `shell` handler/spec and its `ShellToolCallParams`
protocol helper.
- Removed the legacy `local_shell` and `container.exec` handler/spec
plumbing while preserving persisted-history compatibility for old
response items.
- Normalized model/config `default` and `local` shell selections to
`shell_command`.
- Pruned tests that exercised removed raw-shell/local-shell/apply-patch
variants and kept coverage on `shell_command`, unified exec, and
freeform `apply_patch`.

## Verification

- `git diff --check`
- `cargo test -p codex-protocol`
- `cargo test -p codex-tools`
- `cargo test -p codex-core tools::handlers::shell`
- `cargo test -p codex-core tools::spec`
- `cargo test -p codex-core tools::router`
- `cargo test -p codex-core
active_call_preserves_triggering_command_context`
- `cargo test -p codex-core guardian_tests`
- `cargo test -p codex-core --test all shell_serialization`
- `cargo test -p codex-core --test all apply_patch_cli`
- `cargo test -p codex-core --test all shell_command_`
- `cargo test -p codex-core --test all local_shell`
- `cargo test -p codex-core --test all otel::`
- `cargo test -p codex-core --test all hooks::`
- `just fix -p codex-core`
- `just fix -p codex-tools`

codex-rs/protocol/src/models.rs

@@ -1253,30 +1253,6 @@ pub struct SearchToolCallParams {
     pub limit: Option<usize>,
 }
 
-/// If the `name` of a `ResponseItem::FunctionCall` is either `container.exec`
-/// or `shell`, the `arguments` field should deserialize to this struct.
-#[derive(Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
-pub struct ShellToolCallParams {
-    pub command: Vec<String>,
-    pub workdir: Option<String>,
-
-    /// This is the maximum time in milliseconds that the command is allowed to run.
-    #[serde(alias = "timeout")]
-    pub timeout_ms: Option<u64>,
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    #[ts(optional)]
-    pub sandbox_permissions: Option<SandboxPermissions>,
-    /// Suggests a command prefix to persist for future sessions
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    #[ts(optional)]
-    pub prefix_rule: Option<Vec<String>>,
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    #[ts(optional)]
-    pub additional_permissions: Option<AdditionalPermissionProfile>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub justification: Option<String>,
-}
-
 /// If the `name` of a `ResponseItem::FunctionCall` is `shell_command`, the
 /// `arguments` field should deserialize to this struct.
 #[derive(Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
@@ -2545,30 +2521,6 @@ mod tests {
         Ok(())
     }
 
-    #[test]
-    fn deserialize_shell_tool_call_params() -> Result<()> {
-        let json = r#"{
-            "command": ["ls", "-l"],
-            "workdir": "/tmp",
-            "timeout": 1000
-        }"#;
-
-        let params: ShellToolCallParams = serde_json::from_str(json)?;
-        assert_eq!(
-            ShellToolCallParams {
-                command: vec!["ls".to_string(), "-l".to_string()],
-                workdir: Some("/tmp".to_string()),
-                timeout_ms: Some(1000),
-                sandbox_permissions: None,
-                prefix_rule: None,
-                additional_permissions: None,
-                justification: None,
-            },
-            params
-        );
-        Ok(())
-    }
-
     #[test]
     fn wraps_image_user_input_with_tags() -> Result<()> {
         let image_url = "data:image/png;base64,abc".to_string();