refactor: embed generated frontend asset directory

src/trx-client/trx-frontend/trx-frontend-http/build.rs

@@ -2,8 +2,53 @@
 //
 // SPDX-License-Identifier: GPL-2.0-or-later
 
+use std::fmt::Write as _;
+use std::fs;
+use std::path::PathBuf;
 use std::time::{SystemTime, UNIX_EPOCH};
 
+fn generate_asset_manifest() {
+    let manifest_dir = PathBuf::from(std::env::var_os("CARGO_MANIFEST_DIR").expect("manifest dir"));
+    let generated_dir = manifest_dir.join("assets/web/generated");
+    println!("cargo:rerun-if-changed={}", generated_dir.display());
+
+    let mut filenames = fs::read_dir(&generated_dir)
+        .expect("read generated frontend assets")
+        .map(|entry| entry.expect("read generated asset entry"))
+        .filter(|entry| entry.file_type().is_ok_and(|kind| kind.is_file()))
+        .map(|entry| {
+            entry
+                .file_name()
+                .into_string()
+                .expect("UTF-8 asset filename")
+        })
+        .collect::<Vec<_>>();
+    filenames.sort();
+
+    let mut output = String::from(
+        "// Generated by build.rs from committed frontend output.\n\
+         pub const GENERATED_ASSETS: &[(&str, &[u8])] = &[\n",
+    );
+    for filename in filenames {
+        assert!(
+            filename
+                .bytes()
+                .all(|byte| byte.is_ascii_alphanumeric() || b"._-".contains(&byte)),
+            "unsupported generated asset filename: {filename}"
+        );
+        writeln!(
+            output,
+            "    ({filename:?}, include_bytes!(concat!(env!(\"CARGO_MANIFEST_DIR\"), \"/assets/web/generated/\", {filename:?}))),"
+        )
+        .expect("write asset manifest");
+    }
+    output.push_str("];\n");
+
+    let output_path =
+        PathBuf::from(std::env::var_os("OUT_DIR").expect("out dir")).join("generated_assets.rs");
+    fs::write(output_path, output).expect("write generated asset manifest");
+}
+
 fn utc_ymd_from_unix_secs(secs: i64) -> (i32, u32, u32) {
     let days = secs.div_euclid(86_400);
     let z = days + 719_468;
@@ -20,6 +65,7 @@ fn utc_ymd_from_unix_secs(secs: i64) -> (i32, u32, u32) {
 }
 
 fn main() {
+    generate_asset_manifest();
     let secs = match SystemTime::now().duration_since(UNIX_EPOCH) {
         Ok(d) => d.as_secs() as i64,
         Err(_) => 0,