feat(server): auto-build web frontend in build.rs

crates/server/build.rs

@@ -4,8 +4,9 @@ fn main() -> Result<()> {
     if cfg!(target_os = "windows") {
         println!("cargo:rustc-link-lib=Rstrtmgr");
     }
+
     let output = Command::new("git")
-        .args(&["rev-parse", "--short", "HEAD"])
+        .args(["rev-parse", "--short", "HEAD"])
         .output()
         .expect("Failed to get git commit hash");
     let git_hash = String::from_utf8(output.stdout)
@@ -13,5 +14,100 @@ fn main() -> Result<()> {
         .trim()
         .to_string();
     println!("cargo:rustc-env=GIT_HASH={}", git_hash);
+
+    // Build frontend assets
+    build_frontend();
+
     Ok(())
 }
+
+fn build_frontend() {
+    let web_dir = std::path::Path::new("../../web");
+    let dist_dir = web_dir.join("dist");
+
+    // Re-run build.rs when frontend source or dependencies change.
+    println!("cargo:rerun-if-changed=../../web/package.json");
+    println!("cargo:rerun-if-changed=../../web/pnpm-lock.yaml");
+    println!("cargo:rerun-if-changed=../../web/tsconfig.json");
+    println!("cargo:rerun-if-changed=../../web/vite.config.ts");
+    println!("cargo:rerun-if-changed=../../web/index.html");
+    println!("cargo:rerun-if-changed=../../web/src/");
+
+    // Find a working pnpm command. On Windows it may only be available
+    // via cmd.exe (PATH set by the installer, not inherited by bash).
+    let mut pnpm_cmd = None;
+    for candidate in &["pnpm", "pnpm.cmd"] {
+        if command_ok(candidate, &["--version"], web_dir) {
+            pnpm_cmd = Some(*candidate);
+            break;
+        }
+    }
+    // Windows fallback: run through cmd.exe which has the full system PATH.
+    if pnpm_cmd.is_none() && cfg!(target_os = "windows") {
+        if command_ok("cmd", &["/c", "pnpm.cmd", "--version"], web_dir) {
+            pnpm_cmd = Some("cmd");
+        }
+    }
+
+    let Some(cmd) = pnpm_cmd else {
+        // If dist/ already exists (built manually), allow the build to proceed.
+        if dist_dir.exists() {
+            eprintln!(
+                "WARNING: `pnpm` not found in PATH but `web/dist/` exists.\n\
+                 The embedded frontend may be stale. Install pnpm and run\n\
+                 `cd web && pnpm run build` to update it.\n"
+            );
+            return;
+        }
+        eprintln!(
+            "\nERROR: `pnpm` not found. Install Node.js and pnpm, then run:\n\
+               cd web && pnpm install && pnpm run build\n"
+        );
+        std::process::exit(1);
+    };
+
+    if !web_dir.join("node_modules").exists() {
+        // Fresh clone — install dependencies first.
+        eprintln!("Installing frontend dependencies (one-time setup)...");
+        if !run_pnpm(cmd, &["install"], web_dir) {
+            eprintln!("\nERROR: `pnpm install` failed. See output above.\n");
+            std::process::exit(1);
+        }
+    }
+
+    if !run_pnpm(cmd, &["run", "build"], web_dir) {
+        eprintln!("\nERROR: `pnpm run build` failed. See output above.\n");
+        std::process::exit(1);
+    }
+}
+
+fn command_ok(cmd: &str, args: &[&str], dir: &std::path::Path) -> bool {
+    Command::new(cmd)
+        .args(args)
+        .current_dir(dir)
+        .stdout(std::process::Stdio::null())
+        .stderr(std::process::Stdio::null())
+        .status()
+        .map(|s| s.success())
+        .unwrap_or(false)
+}
+
+fn run_pnpm(cmd: &str, args: &[&str], dir: &std::path::Path) -> bool {
+    if cmd == "cmd" {
+        let mut full_args = vec!["/c", "pnpm.cmd"];
+        full_args.extend_from_slice(args);
+        Command::new("cmd")
+            .args(&full_args)
+            .current_dir(dir)
+            .status()
+            .map(|s| s.success())
+            .unwrap_or(false)
+    } else {
+        Command::new(cmd)
+            .args(args)
+            .current_dir(dir)
+            .status()
+            .map(|s| s.success())
+            .unwrap_or(false)
+    }
+}