feat: add Rerun-compatible CLI args for seamless spawn integration (#6)

Add clap CLI argument parsing to dimos-viewer so it accepts the same
flags that rerun_bindings.spawn() passes to the stock rerun binary:

  --port (default 9877)
  --memory-limit (default 75%)
  --server-memory-limit (default 1GiB)
  --hide-welcome-screen
  --expect-data-soon

This enables seamless integration with the Rerun SDK:

  import rerun_bindings
  rerun_bindings.spawn(executable_name='dimos-viewer', port=9877)

No need to fork rerun-sdk or pre-launch the viewer manually.
The DimOS bridge can call rerun_bindings.spawn() directly with
our binary name as a drop-in replacement.

Author: spomichter

Cargo.lock

@@ -2227,6 +2227,7 @@ name = "custom_callback"
 version = "0.30.0-alpha.1+dev"
 dependencies = [
  "bincode",
+ "clap",
  "mimalloc",
  "parking_lot",
  "rerun",

examples/rust/custom_callback/Cargo.toml

@@ -23,6 +23,7 @@ rerun = { path = "../../../crates/top/rerun", default-features = false, features
   "server",
 ] }
 
+clap = { workspace = true, features = ["derive"] }
 bincode.workspace = true
 mimalloc.workspace = true
 parking_lot.workspace = true

examples/rust/custom_callback/src/viewer.rs

@@ -2,6 +2,7 @@ use std::cell::RefCell;
 use std::rc::Rc;
 use std::time::{Duration, Instant, SystemTime, UNIX_EPOCH};
 
+use clap::Parser;
 use custom_callback::interaction::{LcmPublisher, click_event_from_ms};
 use rerun::external::{eframe, re_crash_handler, re_grpc_server, re_log, re_memory, re_viewer};
 
@@ -15,24 +16,61 @@ const LCM_CHANNEL: &str = "/clicked_point#geometry_msgs.PointStamped";
 const CLICK_DEBOUNCE_MS: u64 = 100;
 /// Maximum rapid clicks to log as warning
 const RAPID_CLICK_THRESHOLD: usize = 5;
+/// Default gRPC listen port (9877 to avoid conflict with stock Rerun on 9876)
+const DEFAULT_PORT: u16 = 9877;
+
+/// DimOS Interactive Viewer — a custom Rerun viewer with LCM click-to-navigate.
+///
+/// Accepts the same CLI flags as the stock `rerun` binary so it can be spawned
+/// seamlessly via `rerun_bindings.spawn(executable_name="dimos-viewer")`.
+#[derive(Parser, Debug)]
+#[command(name = "dimos-viewer", version, about)]
+struct Args {
+    /// The gRPC port to listen on for incoming SDK connections.
+    #[arg(long, default_value_t = DEFAULT_PORT)]
+    port: u16,
+
+    /// An upper limit on how much memory the viewer should use.
+    /// When this limit is reached, the oldest data will be dropped.
+    /// Examples: "75%", "16GB".
+    #[arg(long, default_value = "75%")]
+    memory_limit: String,
+
+    /// An upper limit on how much memory the gRPC server should use.
+    /// Examples: "1GiB", "50%".
+    #[arg(long, default_value = "1GiB")]
+    server_memory_limit: String,
+
+    /// Hide the Rerun welcome screen.
+    #[arg(long)]
+    hide_welcome_screen: bool,
+
+    /// Hint that data will arrive shortly (suppresses "waiting for data" message).
+    #[arg(long)]
+    expect_data_soon: bool,
+}
 
 #[tokio::main]
 async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let args = Args::parse();
+
     let main_thread_token = re_viewer::MainThreadToken::i_promise_i_am_on_the_main_thread();
     re_log::setup_logging();
     re_crash_handler::install_crash_handlers(re_viewer::build_info());
 
     // Listen for gRPC connections from Rerun's logging SDKs.
+    let listen_addr = format!("0.0.0.0:{}", args.port);
+    re_log::info!("Listening for SDK connections on {listen_addr}");
     let rx_log = re_grpc_server::spawn_with_recv(
-        "0.0.0.0:9877".parse()?,
+        listen_addr.parse()?,
         Default::default(),
         re_grpc_server::shutdown::never(),
     );
 
     // Create LCM publisher for click events
     let lcm_publisher = LcmPublisher::new(LCM_CHANNEL.to_string())
         .expect("Failed to create LCM publisher");
-    re_log::info!("LCM publisher created for channel: {}", LCM_CHANNEL);
+    re_log::info!("LCM publisher created for channel: {LCM_CHANNEL}");
 
     // State for debouncing and rapid click detection
     let last_click_time = Rc::new(RefCell::new(Instant::now()));
@@ -108,7 +146,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
                                         );
                                     }
                                     Err(err) => {
-                                        re_log::error!("Failed to publish LCM click event: {:?}", err);
+                                        re_log::error!("Failed to publish LCM click event: {err:?}");
                                     }
                                 }
                             }
@@ -121,8 +159,8 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
 
                     if !has_position && no_position_count > 0 {
                         re_log::trace!(
-                            "Selection change without position data ({} items). This is normal for hover/keyboard navigation.",
-                            no_position_count
+                            "Selection change without position data ({no_position_count} items). \
+                             This is normal for hover/keyboard navigation."
                         );
                     }
                 }