core: use codex-tools config types directly (#16504)

## Why

`codex-rs/tools/src/lib.rs` already defines the [canonical `codex_tools`
export
surface](bf081b9e28/codex-rs/tools/src/lib.rs (L83-L88))
for `ToolsConfig`, `ToolsConfigParams`, and the shell backend config
types. Re-exporting those same types from `core/src/tools/spec.rs` gives
`codex-core` two import paths for one API and blurs which crate owns
those config definitions.

This PR removes that duplicate path so `codex-core` callsites depend on
`codex_tools` directly.

## What

- Remove the five `codex_tools` re-exports from
`core/src/tools/spec.rs`.
- Update `codex-core` production and test callsites to import
`ShellCommandBackendConfig`, `ToolsConfig`, `ToolsConfigParams`,
`UnifiedExecShellMode`, and `ZshForkConfig` from `codex_tools`.

## Verification

- Ran `cargo test -p codex-core`.
- The package run is currently red in five unrelated config tests in
`core/src/config/config_tests.rs` (`approvals_reviewer_*` and
`smart_approvals_alias_*`), while the tool/spec and shell tests touched
by this import cleanup passed.

codex-rs/core/src/codex.rs

@@ -347,8 +347,6 @@ use crate::tools::network_approval::build_network_policy_decider;
 use crate::tools::parallel::ToolCallRuntime;
 use crate::tools::router::ToolRouterParams;
 use crate::tools::sandboxing::ApprovalStore;
-use crate::tools::spec::ToolsConfig;
-use crate::tools::spec::ToolsConfigParams;
 use crate::turn_diff_tracker::TurnDiffTracker;
 use crate::turn_timing::TurnTimingState;
 use crate::turn_timing::record_turn_ttfm_metric;
@@ -375,6 +373,8 @@ use codex_protocol::protocol::CodexErrorInfo;
 use codex_protocol::protocol::InitialHistory;
 use codex_protocol::protocol::NonSteerableTurnKind;
 use codex_protocol::user_input::UserInput;
+use codex_tools::ToolsConfig;
+use codex_tools::ToolsConfigParams;
 use codex_utils_absolute_path::AbsolutePathBuf;
 use codex_utils_readiness::Readiness;
 use codex_utils_readiness::ReadinessFlag;

codex-rs/core/src/tools/handlers/shell.rs

@@ -37,9 +37,9 @@ use crate::tools::runtimes::shell::ShellRequest;
 use crate::tools::runtimes::shell::ShellRuntime;
 use crate::tools::runtimes::shell::ShellRuntimeBackend;
 use crate::tools::sandboxing::ToolCtx;
-use crate::tools::spec::ShellCommandBackendConfig;
 use codex_features::Feature;
 use codex_protocol::models::PermissionProfile;
+use codex_tools::ShellCommandBackendConfig;
 
 pub struct ShellHandler;
 

codex-rs/core/src/tools/handlers/unified_exec.rs

@@ -21,7 +21,6 @@ use crate::tools::registry::PostToolUsePayload;
 use crate::tools::registry::PreToolUsePayload;
 use crate::tools::registry::ToolHandler;
 use crate::tools::registry::ToolKind;
-use crate::tools::spec::UnifiedExecShellMode;
 use crate::unified_exec::ExecCommandRequest;
 use crate::unified_exec::UnifiedExecContext;
 use crate::unified_exec::UnifiedExecProcessManager;
@@ -31,6 +30,7 @@ use codex_features::Feature;
 use codex_otel::SessionTelemetry;
 use codex_otel::metrics::names::TOOL_CALL_UNIFIED_EXEC_METRIC;
 use codex_protocol::models::PermissionProfile;
+use codex_tools::UnifiedExecShellMode;
 use serde::Deserialize;
 use std::path::PathBuf;
 use std::sync::Arc;

codex-rs/core/src/tools/handlers/unified_exec_tests.rs

@@ -2,9 +2,10 @@ use super::*;
 use crate::shell::default_user_shell;
 use crate::tools::handlers::parse_arguments_with_base_path;
 use crate::tools::handlers::resolve_workdir_base_path;
-use crate::tools::spec::ZshForkConfig;
 use codex_protocol::models::FileSystemPermissions;
 use codex_protocol::models::PermissionProfile;
+use codex_tools::UnifiedExecShellMode;
+use codex_tools::ZshForkConfig;
 use codex_utils_absolute_path::AbsolutePathBuf;
 use pretty_assertions::assert_eq;
 use std::fs;

codex-rs/core/src/tools/router.rs

@@ -8,7 +8,6 @@ use crate::tools::context::ToolInvocation;
 use crate::tools::context::ToolPayload;
 use crate::tools::registry::AnyToolResult;
 use crate::tools::registry::ToolRegistry;
-use crate::tools::spec::ToolsConfig;
 use crate::tools::spec::build_specs_with_discoverable_tools;
 use codex_protocol::dynamic_tools::DynamicToolSpec;
 use codex_protocol::models::LocalShellAction;
@@ -18,6 +17,7 @@ use codex_protocol::models::ShellToolCallParams;
 use codex_tools::ConfiguredToolSpec;
 use codex_tools::DiscoverableTool;
 use codex_tools::ToolSpec;
+use codex_tools::ToolsConfig;
 use rmcp::model::Tool;
 use std::collections::HashMap;
 use std::sync::Arc;

codex-rs/core/src/tools/runtimes/shell/zsh_fork_backend.rs

@@ -5,8 +5,8 @@ use crate::tools::runtimes::unified_exec::UnifiedExecRequest;
 use crate::tools::sandboxing::SandboxAttempt;
 use crate::tools::sandboxing::ToolCtx;
 use crate::tools::sandboxing::ToolError;
-use crate::tools::spec::ZshForkConfig;
 use crate::unified_exec::SpawnLifecycleHandle;
+use codex_tools::ZshForkConfig;
 
 pub(crate) struct PreparedUnifiedExecSpawn {
     pub(crate) exec_request: ExecRequest,

codex-rs/core/src/tools/runtimes/unified_exec.rs

@@ -32,7 +32,6 @@ use crate::tools::sandboxing::ToolError;
 use crate::tools::sandboxing::ToolRuntime;
 use crate::tools::sandboxing::sandbox_override_for_first_attempt;
 use crate::tools::sandboxing::with_cached_approval;
-use crate::tools::spec::UnifiedExecShellMode;
 use crate::unified_exec::NoopSpawnLifecycle;
 use crate::unified_exec::UnifiedExecError;
 use crate::unified_exec::UnifiedExecProcess;
@@ -41,6 +40,7 @@ use codex_network_proxy::NetworkProxy;
 use codex_protocol::models::PermissionProfile;
 use codex_protocol::protocol::ReviewDecision;
 use codex_sandboxing::SandboxablePreference;
+use codex_tools::UnifiedExecShellMode;
 use futures::future::BoxFuture;
 use std::collections::HashMap;
 use std::path::PathBuf;

codex-rs/core/src/tools/spec.rs

@@ -23,6 +23,7 @@ use codex_tools::TOOL_SUGGEST_TOOL_NAME;
 use codex_tools::ToolSearchAppSource;
 use codex_tools::ToolSpec;
 use codex_tools::ToolUserShellType;
+use codex_tools::ToolsConfig;
 use codex_tools::ViewImageToolOptions;
 use codex_tools::WaitAgentTimeoutOptions;
 use codex_tools::WebSearchToolOptions;
@@ -73,12 +74,6 @@ use codex_tools::request_user_input_tool_description;
 use codex_tools::tool_spec_to_code_mode_tool_definition;
 use std::collections::HashMap;
 
-pub use codex_tools::ShellCommandBackendConfig;
-pub use codex_tools::ToolsConfig;
-pub use codex_tools::ToolsConfigParams;
-pub use codex_tools::UnifiedExecShellMode;
-pub use codex_tools::ZshForkConfig;
-
 #[cfg(test)]
 pub(crate) use codex_tools::mcp_call_tool_result_output_schema;
 

codex-rs/core/src/tools/spec_tests.rs

@@ -29,9 +29,14 @@ use codex_tools::JsonSchema;
 use codex_tools::ResponsesApiTool;
 use codex_tools::ResponsesApiWebSearchFilters;
 use codex_tools::ResponsesApiWebSearchUserLocation;
+use codex_tools::ShellCommandBackendConfig;
 use codex_tools::SpawnAgentToolOptions;
+use codex_tools::ToolsConfig;
+use codex_tools::ToolsConfigParams;
+use codex_tools::UnifiedExecShellMode;
 use codex_tools::ViewImageToolOptions;
 use codex_tools::WaitAgentTimeoutOptions;
+use codex_tools::ZshForkConfig;
 use codex_tools::create_apply_patch_freeform_tool;
 use codex_tools::create_close_agent_tool_v1;
 use codex_tools::create_close_agent_tool_v2;