feat(cli): include git hash in fe --version output

crates/fe/build.rs

@@ -0,0 +1,28 @@
+use std::process::Command;
+
+fn main() {
+    println!("cargo:rerun-if-changed=.git/HEAD");
+    println!("cargo:rerun-if-env-changed=FE_GIT_HASH");
+
+    if let Ok(override_hash) = std::env::var("FE_GIT_HASH")
+        && !override_hash.trim().is_empty()
+    {
+        println!("cargo:rustc-env=FE_GIT_HASH={}", override_hash.trim());
+        return;
+    }
+
+    let output = Command::new("git")
+        .args(["rev-parse", "--short", "HEAD"])
+        .output();
+
+    let Some(hash) = output
+        .ok()
+        .filter(|o| o.status.success())
+        .map(|o| String::from_utf8_lossy(&o.stdout).trim().to_string())
+        .filter(|s| !s.is_empty())
+    else {
+        return;
+    };
+
+    println!("cargo:rustc-env=FE_GIT_HASH={hash}");
+}

crates/fe/src/main.rs

@@ -17,6 +17,7 @@ mod tree;
 mod workspace_ingot;
 
 use std::fs;
+use std::sync::OnceLock;
 
 use build::build;
 use camino::Utf8PathBuf;
@@ -52,8 +53,18 @@ pub enum BuildEmit {
     Abi,
 }
 
+fn cli_version() -> &'static str {
+    static VERSION: OnceLock<String> = OnceLock::new();
+    VERSION
+        .get_or_init(|| match option_env!("FE_GIT_HASH") {
+            Some(hash) if !hash.is_empty() => format!("{} ({hash})", env!("CARGO_PKG_VERSION")),
+            _ => env!("CARGO_PKG_VERSION").to_string(),
+        })
+        .as_str()
+}
+
 #[derive(Debug, Clone, Parser)]
-#[command(version, about, long_about = None)]
+#[command(version = cli_version(), about, long_about = None)]
 pub struct Options {
     /// Control colored output (auto, always, never).
     #[arg(long, global = true, value_enum, default_value = "auto")]