[codex] Remove codex-core config type shim (#16529)

## Why

This finishes the config-type move out of `codex-core` by removing the
temporary compatibility shim in `codex_core::config::types`. Callers now
depend on `codex-config` directly, which keeps these config model types
owned by the config crate instead of re-expanding `codex-core` as a
transitive API surface.

## What Changed

- Removed the `codex-rs/core/src/config/types.rs` re-export shim and the
`core::config::ApprovalsReviewer` re-export.
- Updated `codex-core`, `codex-cli`, `codex-tui`, `codex-app-server`,
`codex-mcp-server`, and `codex-linux-sandbox` call sites to import
`codex_config::types` directly.
- Added explicit `codex-config` dependencies to downstream crates that
previously relied on the `codex-core` re-export.
- Regenerated `codex-rs/core/config.schema.json` after updating the
config docs path reference.

codex-rs/Cargo.lock

@@ -1407,6 +1407,7 @@ dependencies = [
  "codex-backend-client",
  "codex-chatgpt",
  "codex-cloud-requirements",
+ "codex-config",
  "codex-core",
  "codex-exec-server",
  "codex-features",
@@ -2201,6 +2202,7 @@ version = "0.0.0"
 dependencies = [
  "cc",
  "clap",
+ "codex-config",
  "codex-core",
  "codex-protocol",
  "codex-sandboxing",
@@ -2304,6 +2306,7 @@ version = "0.0.0"
 dependencies = [
  "anyhow",
  "codex-arg0",
+ "codex-config",
  "codex-core",
  "codex-exec-server",
  "codex-features",
@@ -2694,6 +2697,7 @@ dependencies = [
  "codex-chatgpt",
  "codex-cli",
  "codex-cloud-requirements",
+ "codex-config",
  "codex-core",
  "codex-features",
  "codex-feedback",