v2: pin Rust 1.89 and fix sensing-server UI path when run from v2 (#523)

* v2: pin Rust 1.89 for sensing-server dependency chain

ruvector-core 2.0.5, hnsw_rs 0.3.4, and mmap-rs 0.7 require newer Cargo/rustc
than 1.82 (edition2024 manifest, is_multiple_of, stable avx512f target_feature
on x86_64). Add v2/rust-toolchain.toml so cargo build -p
wifi-densepose-sensing-server picks a compatible toolchain.

Signed-off-by: Chaitanya Tata <chaitanya@dotstarconsulting.com>
Co-authored-by: Cursor <cursoragent@cursor.com>

* sensing-server: default UI path for cwd v2/ and coalesce fallbacks

The previous default ../../ui resolves to a non-existent directory when
the binary is run from v2/ (common), so /ui/* returned 404 and the
dashboard appeared broken. Default to ../ui and try ../ui, ./ui,
../../ui when the configured path is missing.

Signed-off-by: Chaitanya Tata <chaitanya@dotstarconsulting.com>
Co-authored-by: Cursor <cursoragent@cursor.com>

---------

Signed-off-by: Chaitanya Tata <chaitanya@dotstarconsulting.com>
Co-authored-by: Cursor <cursoragent@cursor.com>

v2/crates/wifi-densepose-sensing-server/src/cli.rs

@@ -19,8 +19,8 @@ pub struct Args {
     #[arg(long, default_value = "5005")]
     pub udp_port: u16,
 
-    /// Path to UI static files
+    /// Path to UI static files (from `v2/` cwd use `../ui`)
-    #[arg(long, default_value = "../../ui")]
+    #[arg(long, default_value = "../ui")]
     pub ui_path: PathBuf,
 
     /// Tick interval in milliseconds (default 100 ms = 10 fps for smooth pose animation)

v2/crates/wifi-densepose-sensing-server/src/main.rs

@@ -83,8 +83,8 @@ struct Args {
     #[arg(long, default_value = "5005")]
     udp_port: u16,
 
-    /// Path to UI static files
+    /// Path to UI static files (repo `ui/`; from `v2/` use `../ui` or rely on auto-detect)
-    #[arg(long, default_value = "../../ui")]
+    #[arg(long, default_value = "../ui")]
     ui_path: PathBuf,
 
     /// Tick interval in milliseconds (default 100 ms = 10 fps for smooth pose animation)
@@ -4341,6 +4341,25 @@ async fn broadcast_tick_task(state: SharedState, tick_ms: u64) {
 
 // ── Main ─────────────────────────────────────────────────────────────────────
 
+/// If `--ui-path` points nowhere (wrong cwd), try common repo layouts relative to cwd.
+fn coalesce_ui_path(initial: std::path::PathBuf) -> std::path::PathBuf {
+    if initial.is_dir() {
+        return initial;
+    }
+    for rel in &["../ui", "./ui", "../../ui"] {
+        let p = std::path::PathBuf::from(rel);
+        if p.is_dir() {
+            warn!(
+                "UI path {} not found; using {} (set --ui-path explicitly if wrong)",
+                initial.display(),
+                p.display()
+            );
+            return p;
+        }
+    }
+    initial
+}
+
 #[tokio::main]
 async fn main() {
     // Initialize tracing
@@ -4351,7 +4370,8 @@ async fn main() {
         )
         .init();
 
-    let args = Args::parse();
+    let mut args = Args::parse();
+    args.ui_path = coalesce_ui_path(args.ui_path);
 
     // Handle --benchmark mode: run vital sign benchmark and exit
     if args.benchmark {

v2/rust-toolchain.toml

@@ -0,0 +1,7 @@
+# wifi-densepose-sensing-server (ruvector-mincut -> ruvector-core / hnsw_rs / mmap-rs):
+# - mmap-rs 0.7: Cargo must accept edition 2024 in a dependency manifest (1.85+).
+# - hnsw_rs 0.3.4: u*.is_multiple_of (1.86+).
+# - ruvector-core 2.0.5 x86_64: #[target_feature(enable = "avx512f")] (1.89+ stable).
+[toolchain]
+channel = "1.89"
+profile = "minimal"