Add OpenWrt ipk packaging + split client/server binaries

OpenWrt package (deploy/openwrt/):
- build-ipk.sh: creates .ipk from pre-built binary (no SDK needed)
- Makefile: for OpenWrt SDK integration
- ProCD init script with UCI config
- Supports all architectures (x86_64, aarch64, mipsel, mips)

Split binaries for embedded (src/bin/):
- btest-client: client-only, no server/syslog/csv
- btest-server: server-only, no client
- release-small profile: opt-level=z + panic=abort

Sizes (compressed .tar.gz):
  Full btest:    ~1 MB
  btest-client:  ~500 KB (release-small)
  btest-server:  ~550 KB (release-small)

Install on OpenWrt:
  opkg install btest-rs_0.6.0-1_x86_64.ipk

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/bin/client_only.rs

@@ -0,0 +1,127 @@
+//! btest-client: minimal bandwidth test client for embedded/OpenWrt systems.
+//!
+//! Stripped-down client that connects to MikroTik btest servers.
+//! No server mode, no syslog, smaller binary footprint.
+//!
+//! Build: cargo build --profile release-small --bin btest-client
+
+use clap::Parser;
+use std::sync::atomic::Ordering;
+
+#[derive(Parser)]
+#[command(name = "btest-client", about = "MikroTik Bandwidth Test client", version)]
+struct Cli {
+    /// Server address to connect to
+    #[arg(short = 'c', long = "client", required = true)]
+    host: String,
+
+    /// Transmit data (upload)
+    #[arg(short = 't', long = "transmit")]
+    transmit: bool,
+
+    /// Receive data (download)
+    #[arg(short = 'r', long = "receive")]
+    receive: bool,
+
+    /// Use UDP
+    #[arg(short = 'u', long = "udp")]
+    udp: bool,
+
+    /// Bandwidth limit (e.g., 100M)
+    #[arg(short = 'b', long = "bandwidth")]
+    bandwidth: Option<String>,
+
+    /// Port
+    #[arg(short = 'P', long = "port", default_value_t = 2000)]
+    port: u16,
+
+    /// Username
+    #[arg(short = 'a', long = "authuser")]
+    auth_user: Option<String>,
+
+    /// Password
+    #[arg(short = 'p', long = "authpass")]
+    auth_pass: Option<String>,
+
+    /// NAT mode
+    #[arg(short = 'n', long = "nat")]
+    nat: bool,
+
+    /// Duration in seconds (0=unlimited)
+    #[arg(short = 'd', long = "duration", default_value_t = 0)]
+    duration: u64,
+
+    /// Verbose
+    #[arg(short = 'v', long = "verbose", action = clap::ArgAction::Count)]
+    verbose: u8,
+}
+
+#[tokio::main]
+async fn main() -> anyhow::Result<()> {
+    let cli = Cli::parse();
+
+    let filter = match cli.verbose {
+        0 => "info",
+        1 => "debug",
+        _ => "trace",
+    };
+    tracing_subscriber::fmt()
+        .with_env_filter(
+            tracing_subscriber::EnvFilter::try_from_default_env()
+                .unwrap_or_else(|_| tracing_subscriber::EnvFilter::new(filter)),
+        )
+        .with_target(false)
+        .init();
+
+    btest_rs::cpu::start_sampler();
+
+    if !cli.transmit && !cli.receive {
+        eprintln!("Error: specify -t (transmit) and/or -r (receive)");
+        std::process::exit(1);
+    }
+
+    let direction = match (cli.transmit, cli.receive) {
+        (true, false) => btest_rs::protocol::CMD_DIR_RX,
+        (false, true) => btest_rs::protocol::CMD_DIR_TX,
+        (true, true) => btest_rs::protocol::CMD_DIR_BOTH,
+        _ => unreachable!(),
+    };
+
+    let bw = match &cli.bandwidth {
+        Some(b) => btest_rs::bandwidth::parse_bandwidth(b)?,
+        None => 0,
+    };
+
+    let (tx_speed, rx_speed) = match direction {
+        btest_rs::protocol::CMD_DIR_TX => (bw, 0),
+        btest_rs::protocol::CMD_DIR_RX => (0, bw),
+        _ => (bw, bw),
+    };
+
+    let state = btest_rs::bandwidth::BandwidthState::new();
+    let state_clone = state.clone();
+
+    let host = cli.host.clone();
+    let client_fut = btest_rs::client::run_client(
+        &host, cli.port, direction, cli.udp,
+        tx_speed, rx_speed,
+        cli.auth_user, cli.auth_pass, cli.nat,
+        state_clone,
+    );
+
+    if cli.duration > 0 {
+        match tokio::time::timeout(
+            std::time::Duration::from_secs(cli.duration),
+            client_fut,
+        ).await {
+            Ok(r) => { let _ = r?; }
+            Err(_) => {
+                state.running.store(false, Ordering::SeqCst);
+            }
+        }
+    } else {
+        let _ = client_fut.await?;
+    }
+
+    Ok(())
+}

src/bin/server_only.rs

@@ -0,0 +1,62 @@
+//! btest-server: minimal bandwidth test server for embedded/OpenWrt systems.
+//!
+//! Stripped-down server that accepts MikroTik client connections.
+//! No client mode, no syslog, no CSV, smaller binary footprint.
+//!
+//! Build: cargo build --profile release-small --bin btest-server
+
+use clap::Parser;
+
+#[derive(Parser)]
+#[command(name = "btest-server", about = "MikroTik Bandwidth Test server", version)]
+struct Cli {
+    /// Port
+    #[arg(short = 'P', long = "port", default_value_t = 2000)]
+    port: u16,
+
+    /// IPv4 listen address
+    #[arg(long = "listen", default_value = "0.0.0.0")]
+    listen_addr: String,
+
+    /// Username
+    #[arg(short = 'a', long = "authuser")]
+    auth_user: Option<String>,
+
+    /// Password
+    #[arg(short = 'p', long = "authpass")]
+    auth_pass: Option<String>,
+
+    /// Use EC-SRP5 authentication
+    #[arg(long = "ecsrp5")]
+    ecsrp5: bool,
+
+    /// Verbose
+    #[arg(short = 'v', long = "verbose", action = clap::ArgAction::Count)]
+    verbose: u8,
+}
+
+#[tokio::main]
+async fn main() -> anyhow::Result<()> {
+    let cli = Cli::parse();
+
+    let filter = match cli.verbose {
+        0 => "info",
+        1 => "debug",
+        _ => "trace",
+    };
+    tracing_subscriber::fmt()
+        .with_env_filter(
+            tracing_subscriber::EnvFilter::try_from_default_env()
+                .unwrap_or_else(|_| tracing_subscriber::EnvFilter::new(filter)),
+        )
+        .with_target(false)
+        .init();
+
+    btest_rs::cpu::start_sampler();
+
+    let v4 = if cli.listen_addr.eq_ignore_ascii_case("none") { None } else { Some(cli.listen_addr) };
+
+    tracing::info!("btest-server starting on port {}", cli.port);
+    btest_rs::server::run_server(cli.port, cli.auth_user, cli.auth_pass, cli.ecsrp5, v4, None).await?;
+    Ok(())
+}