feat(cli): match Composer's --version output format

Replace clap's built-in --version with custom handler that outputs
Composer-compatible version info: Mozart version line, PHP version
with binary path, and diagnose hint. Add detect_php_version_and_binary()
to mozart-core platform module.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

4 files changed, 49 insertions, 8 deletions

diff --git a/crates/mozart/src/commands.rs b/crates/mozart/src/commands.rs
index 968763f..e633526 100644
--- a/crates/mozart/src/commands.rs
+++ b/crates/mozart/src/commands.rs
@@ -35,10 +35,14 @@ pub mod update;
 pub mod validate;
 
 #[derive(clap::Parser)]
-#[command(name = "mozart", version, about = "A PHP dependency manager")]
+#[command(name = "mozart", about = "A PHP dependency manager")]
 pub struct Cli {
     #[command(subcommand)]
-    pub command: Commands,
+    pub command: Option<Commands>,
+
+    /// Display version information
+    #[arg(short = 'V', long = "version")]
+    pub version: bool,
 
     /// Increase the verbosity of messages: 1 for normal, 2 for more verbose, 3 for debug
     #[arg(short, long, action = clap::ArgAction::Count, global = true)]
@@ -238,7 +242,7 @@ impl Commands {
     }
 }
 
-#[tracing::instrument(skip(cli), fields(command = cli.command.name()))]
+#[tracing::instrument(skip(cli), fields(command = cli.command.as_ref().map(|c| c.name()).unwrap_or("none")))]
 pub async fn execute(cli: &Cli) -> anyhow::Result<()> {
     let console = mozart_core::console::Console::new(
         cli.verbose,
@@ -247,7 +251,8 @@ pub async fn execute(cli: &Cli) -> anyhow::Result<()> {
         cli.no_ansi,
         cli.no_interaction,
     );
-    match &cli.command {
+    let command = cli.command.as_ref().expect("command must be set");
+    match command {
         Commands::About(args) => about::execute(args, cli, &console).await,
         Commands::Archive(args) => archive::execute(args, cli, &console).await,
         Commands::Audit(args) => audit::execute(args, cli, &console).await,
diff --git a/crates/mozart/src/commands/bump.rs b/crates/mozart/src/commands/bump.rs
index b322dbe..e1b5f63 100644
--- a/crates/mozart/src/commands/bump.rs
+++ b/crates/mozart/src/commands/bump.rs
@@ -311,12 +311,13 @@ mod tests {
 
     fn make_cli(working_dir: &std::path::Path) -> super::super::Cli {
         super::super::Cli {
-            command: super::super::Commands::Bump(BumpArgs {
+            command: Some(super::super::Commands::Bump(BumpArgs {
                 packages: vec![],
                 dev_only: false,
                 no_dev_only: false,
                 dry_run: false,
-            }),
+            })),
+            version: false,
             verbose: 0,
             profile: false,
             no_plugins: false,
diff --git a/crates/mozart/src/commands/global.rs b/crates/mozart/src/commands/global.rs
index 97d56d2..dfa4fc2 100644
--- a/crates/mozart/src/commands/global.rs
+++ b/crates/mozart/src/commands/global.rs
@@ -221,7 +221,7 @@ mod tests {
     fn test_global_args_has_correct_command() {
         // Verify GlobalArgs parses correctly through the CLI
         let cli = Cli::try_parse_from(["mozart", "global", "require", "vendor/package"]).unwrap();
-        if let Commands::Global(args) = cli.command {
+        if let Some(Commands::Global(args)) = cli.command {
             assert_eq!(args.command_name, "require");
             assert_eq!(args.args, vec!["vendor/package"]);
         } else {
@@ -234,7 +234,7 @@ mod tests {
         // Verify hyphen values in trailing args are accepted
         let cli = Cli::try_parse_from(["mozart", "global", "require", "vendor/pkg", "--no-update"])
             .unwrap();
-        if let Commands::Global(args) = cli.command {
+        if let Some(Commands::Global(args)) = cli.command {
             assert_eq!(args.command_name, "require");
             assert!(args.args.contains(&"--no-update".to_string()));
         } else {
diff --git a/crates/mozart/src/main.rs b/crates/mozart/src/main.rs
index ed7c4ad..8201d87 100644
--- a/crates/mozart/src/main.rs
+++ b/crates/mozart/src/main.rs
@@ -40,6 +40,41 @@ fn init_tracing(profile: bool, verbose: u8, quiet: bool) {
 #[tokio::main]
 async fn main() {
     let cli = commands::Cli::parse();
+
+    if cli.version {
+        let build_date = option_env!("MOZART_BUILD_DATE").unwrap_or("source");
+        // Line 1 (stdout): getLongVersion() equivalent
+        println!(
+            "{}",
+            mozart_core::console_format!(
+                "<info>Mozart</info> version <comment>{}</comment> {}",
+                env!("CARGO_PKG_VERSION"),
+                build_date
+            )
+        );
+        // Line 2 (stderr): PHP version + binary path (matches Composer's output)
+        let (php_version, php_binary) = mozart_core::platform::detect_php_version_and_binary()
+            .unwrap_or_else(|| ("not found".into(), "php".into()));
+        eprintln!(
+            "{}",
+            mozart_core::console_format!(
+                "<info>PHP</info> version <comment>{}</comment> ({})",
+                php_version,
+                php_binary
+            )
+        );
+        // Line 3 (stderr): diagnose hint
+        eprintln!("Run the \"diagnose\" command to get more detailed diagnostics output.");
+        return;
+    }
+
+    let Some(ref _cmd) = cli.command else {
+        use clap::CommandFactory;
+        commands::Cli::command().print_help().ok();
+        println!();
+        return;
+    };
+
     init_tracing(cli.profile, cli.verbose, cli.quiet);
     match commands::execute(&cli).await {
         Ok(()) => {}