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/src/precomputed_exports_tests.rs

@@ -0,0 +1,69 @@
+use crate::GenerateTsOptions;
+use crate::generate_internal_json_schema;
+use crate::generate_json_with_experimental;
+use crate::generate_ts_with_options;
+use crate::precomputed_exports::GENERATED_TS_HEADER;
+use crate::precomputed_exports::decode_precomputed_exports;
+use crate::schema_fixtures::collect_export_files_recursive;
+use anyhow::Context;
+use anyhow::Result;
+use pretty_assertions::assert_eq;
+use std::path::Path;
+
+#[test]
+fn precomputed_exports_are_written_to_disk() -> Result<()> {
+    let output_dir = tempfile::tempdir().context("create export temp dir")?;
+    let typescript_dir = output_dir.path().join("typescript");
+    let json_dir = output_dir.path().join("json");
+    let internal_json_dir = output_dir.path().join("internal-json");
+
+    generate_ts_with_options(
+        &typescript_dir,
+        /*prettier*/ None,
+        GenerateTsOptions::default(),
+    )?;
+    generate_json_with_experimental(&json_dir, /*experimental_api*/ false)?;
+    generate_internal_json_schema(&internal_json_dir)?;
+
+    let exports = decode_precomputed_exports(/*experimental_api*/ false)?;
+    assert_eq!(
+        collect_export_files_recursive(&typescript_dir)?,
+        exports.typescript
+    );
+    assert_eq!(
+        collect_export_files_recursive(&json_dir)?,
+        exports.json_schema
+    );
+    assert_eq!(
+        collect_export_files_recursive(&internal_json_dir)?,
+        exports.internal_json_schema
+    );
+    Ok(())
+}
+
+#[test]
+fn typescript_export_options_preserve_generator_behavior() -> Result<()> {
+    let output_dir = tempfile::tempdir().context("create TypeScript export temp dir")?;
+    generate_ts_with_options(
+        output_dir.path(),
+        /*prettier*/ None,
+        GenerateTsOptions {
+            generate_indices: false,
+            ensure_headers: false,
+            ..GenerateTsOptions::default()
+        },
+    )?;
+
+    let files = collect_export_files_recursive(output_dir.path())?;
+    assert!(!files.keys().any(|path| {
+        Path::new(path)
+            .file_name()
+            .is_some_and(|name| name == "index.ts")
+    }));
+    assert!(
+        files
+            .values()
+            .all(|contents| !contents.starts_with(GENERATED_TS_HEADER))
+    );
+    Ok(())
+}