Precompute app-server protocol exports (#36212)

## Why

Normal app-server protocol builds do not need the `ts-rs` and `schemars`
implementations used to generate schema exports.

## What changed

- Embed compressed stable and experimental TypeScript and JSON schema exports,
  and serve the existing export APIs from those artifacts.
- Use no-op schema derives in non-test builds while keeping the real generators
  available for fixture regeneration and tests.
- Move schema fixture regeneration behind a Python helper and update
  `just write-app-server-schema --experimental` to refresh the experimental
  embedded exports.

## Testing

- Verify embedded exports match freshly generated stable and experimental
  schemas.
- Verify export options and on-disk output remain compatible.

GitOrigin-RevId: e8536338b457e6eec34bdf29ec0684144bd13734

codex-rs/app-server-protocol-noop-macros/BUILD.bazel

@@ -0,0 +1,7 @@
+load("//:defs.bzl", "codex_rust_crate")
+
+codex_rust_crate(
+    name = "app-server-protocol-noop-macros",
+    crate_name = "codex_app_server_protocol_noop_macros",
+    proc_macro = True,
+)

codex-rs/app-server-protocol-noop-macros/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "codex-app-server-protocol-noop-macros"
+version.workspace = true
+edition.workspace = true
+license.workspace = true
+
+[lib]
+proc-macro = true
+test = false
+doctest = false
+
+[lints]
+workspace = true

codex-rs/app-server-protocol-noop-macros/src/lib.rs

@@ -0,0 +1,20 @@
+//! No-op schema derives for production app-server protocol builds.
+//!
+//! The real `ts-rs` and `schemars` derives are only needed when regenerating
+//! the vendored protocol exports. Normal builds retain the annotations so the
+//! protocol definitions stay readable, but use these derives to avoid
+//! generating implementations that cannot be reached at runtime.
+
+use proc_macro::TokenStream;
+
+/// Accepts `#[schemars(...)]` helper attributes without generating an impl.
+#[proc_macro_derive(JsonSchema, attributes(schemars))]
+pub fn derive_json_schema(_input: TokenStream) -> TokenStream {
+    TokenStream::new()
+}
+
+/// Accepts `#[ts(...)]` helper attributes without generating an impl.
+#[proc_macro_derive(TS, attributes(ts))]
+pub fn derive_ts(_input: TokenStream) -> TokenStream {
+    TokenStream::new()
+}