WVDSH-1280: add first-run splash with ASCII glyph

Render the Wavedash glyph (diamond + two chevrons) as bright-mono half-block
ASCII art, sampled from the source SVG. Shown once the first time the CLI is
run on an interactive terminal (gated by a marker in the config dir), and as
the home screen when `wavedash` is run with no subcommand. Skipped for
non-TTY output (pipes/CI) and the `update` command.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: franzwarning

Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "wavedash"
-version = "0.1.88"
+version = "0.1.89"
 edition = "2021"
 authors = ["Wavedash Team"]
 description = "Cross-platform CLI tool for uploading game projects to wavedash.com"

Cargo.toml

@@ -8,6 +8,7 @@ mod init;
 mod publish;
 mod stats;
 mod updater;
+mod welcome;
 
 use achievements::{
     handle_achievement_create, handle_achievement_delete, handle_achievement_update,
@@ -52,7 +53,7 @@ struct Cli {
     #[arg(long, global = true, help = "Enable verbose output")]
     verbose: bool,
     #[command(subcommand)]
-    command: Commands,
+    command: Option<Commands>,
 }
 
 #[derive(Subcommand)]
@@ -367,14 +368,27 @@ async fn main() {
 async fn run() -> Result<()> {
     let cli = Cli::parse();
 
+    // Bare `wavedash` (no subcommand) is the home screen: show the splash and
+    // point at --help.
+    let Some(command) = cli.command else {
+        welcome::show_home();
+        return Ok(());
+    };
+
+    // Greet on the very first interactive run (skip for `update`, which has its
+    // own focused output).
+    if !matches!(command, Commands::Update) {
+        welcome::show_first_run_if_needed();
+    }
+
     // Check for updates in background, but skip if the user is already running `update`
-    let update_handle = if matches!(cli.command, Commands::Update) {
+    let update_handle = if matches!(command, Commands::Update) {
         None
     } else {
         Some(updater::check_for_update())
     };
 
-    match cli.command {
+    match command {
         Commands::Init => {
             handle_init().await?;
         }

src/main.rs

@@ -0,0 +1,105 @@
+use crate::config;
+use colored::Colorize;
+use std::fs;
+use std::io::IsTerminal;
+use std::path::PathBuf;
+
+/// The Wavedash glyph — a diamond chasing two chevrons — rendered with
+/// half-block characters (▀▄█) so the diagonals stay crisp at this size.
+/// Sampled from the source `glyph.svg`; 20 columns wide, 10 rows tall.
+const GLYPH: &str = "        ▄██▄
+         ▀███▄
+    ▄█▄    ▀███▄
+     ▀██▄    ▀███▄
+▄█▄    ▀██▄    ▀███▄
+▀█▀    ▄██▀    ▄███▀
+     ▄██▀    ▄███▀
+    ▀█▀    ▄███▀
+         ▄███▀
+        ▀██▀";
+
+/// Width (in columns) the glyph is padded to so the wordmark lines up.
+const GLYPH_WIDTH: usize = 20;
+
+fn marker_path() -> Option<PathBuf> {
+    config::wavedash_dir().ok().map(|d| d.join(".welcomed"))
+}
+
+/// Print the first-run splash once, the very first time the CLI is run on an
+/// interactive terminal. A marker file under the wavedash config dir records
+/// that we've greeted, so it never shows again. No-ops when stdout isn't a TTY
+/// (piped output, CI) so it never pollutes machine-readable output.
+pub fn show_first_run_if_needed() {
+    if !std::io::stdout().is_terminal() {
+        return;
+    }
+    let Some(marker) = marker_path() else {
+        return;
+    };
+    if marker.exists() {
+        return;
+    }
+
+    print_splash();
+    mark_welcomed();
+}
+
+/// The home screen shown when `wavedash` is run with no subcommand. Always
+/// prints the splash (this is an explicit "show me the overview" invocation)
+/// and points at `--help` for the full command list. Also records the greeting
+/// so a later first command doesn't greet again.
+pub fn show_home() {
+    print_splash();
+    println!(
+        "  Run {} to see every command.",
+        "wavedash --help".bold().bright_white()
+    );
+    println!();
+    mark_welcomed();
+}
+
+/// Record that we've greeted so the first-run banner never repeats. Failures
+/// here must never block the CLI, so errors are intentionally ignored.
+fn mark_welcomed() {
+    let Some(marker) = marker_path() else {
+        return;
+    };
+    if let Some(parent) = marker.parent() {
+        let _ = fs::create_dir_all(parent);
+    }
+    let _ = fs::write(&marker, b"1");
+}
+
+fn print_splash() {
+    let lines: Vec<&str> = GLYPH.lines().collect();
+    let wordmark = "W A V E D A S H".bold().bright_white();
+    let tagline = "Play anywhere instantly".dimmed();
+
+    println!();
+    for (i, line) in lines.iter().enumerate() {
+        // Pad the plain text first, then colorize — coloring before padding
+        // would pad the ANSI escape codes and break alignment.
+        let glyph = format!("{:<width$}", line, width = GLYPH_WIDTH)
+            .bright_white()
+            .bold();
+        match i {
+            4 => println!("  {}    {}", glyph, wordmark),
+            5 => println!("  {}    {}", glyph, tagline),
+            _ => println!("  {}", glyph),
+        }
+    }
+
+    println!();
+    println!("  {}", "Get started".bold().bright_white());
+    let steps = [
+        ("wavedash auth login", "Sign in to your account"),
+        ("wavedash init", "Set up this project"),
+        ("wavedash dev", "Preview your game locally"),
+        ("wavedash build push", "Upload a build"),
+    ];
+    for (cmd, desc) in steps {
+        let cmd = format!("{:<22}", cmd).bold();
+        println!("    {} {} {}", "$".dimmed(), cmd, desc.dimmed());
+    }
+    println!();
+}