[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/linux-sandbox/Cargo.toml

@@ -17,6 +17,7 @@ workspace = true
 
 [target.'cfg(target_os = "linux")'.dependencies]
 clap = { workspace = true, features = ["derive"] }
+codex-config = { workspace = true }
 codex-core = { workspace = true }
 codex-protocol = { workspace = true }
 codex-sandboxing = { workspace = true }