fix(discovery): normalize Bonjour names by stripping .local

Discovery now caches by service-instance label, but the announcer's
choice of label is platform-dependent: macOS's `hostname::get()`
returns the FQDN (`Foo.local`) while Linux's returns the short name
(`omarchy`). Without normalization this works asymmetrically — a
config of `omarchy.local` for a Linux peer wouldn't match the cached
`omarchy` key.

Add `normalize_mdns_name` (lower-case, drop trailing `.`, drop
`.local` suffix) and apply it on both insert (start_browse) and
lookup (`peer_primary_ip`, `should_attempt`, `connect_to_handle`).
The `.local` domain is implied for everything mDNS-SD touches, so
collapsing it on both sides is lossless and matches how `dns-sd`
and Bonjour APIs treat instance labels in their wire form.

Author: jondkinney

src/connect.rs

@@ -1,6 +1,6 @@
 use crate::client::ClientManager;
 use crate::config::local_commit;
-use crate::discovery::PrimaryCache;
+use crate::discovery::{PrimaryCache, normalize_mdns_name};
 use lan_mouse_ipc::{ClientHandle, DEFAULT_PORT};
 use lan_mouse_proto::{MAX_EVENT_SIZE, ProtoEvent};
 use local_channel::mpsc::{Receiver, Sender, channel};
@@ -282,7 +282,7 @@ impl LanMouseConnection {
     fn should_attempt(&self, handle: ClientHandle) -> bool {
         let ips = self.client_manager.get_ips(handle).unwrap_or_default();
         let primary = self.client_manager.get_hostname(handle).and_then(|h| {
-            let key = h.strip_suffix('.').unwrap_or(&h).to_ascii_lowercase();
+            let key = normalize_mdns_name(&h);
             self.primary_hints.borrow().get(&key).copied()
         });
         let sig = signature_of(&ips, primary);
@@ -326,7 +326,7 @@ async fn connect_to_handle(
         // so a healthy primary almost always wins regardless of
         // raw RTT ordering.
         let primary_ip = client_manager.get_hostname(handle).and_then(|h| {
-            let key = h.strip_suffix('.').unwrap_or(&h).to_ascii_lowercase();
+            let key = normalize_mdns_name(&h);
             primary_hints.borrow().get(&key).copied()
         });
         let preferred = primary_ip.map(|ip| SocketAddr::new(ip, port));

src/discovery.rs

@@ -81,6 +81,18 @@ fn instance_from_fullname<'a>(fullname: &'a str, service_type: &str) -> &'a str
     fullname.strip_suffix(&suffix).unwrap_or(fullname)
 }
 
+/// Canonicalize a Bonjour/mDNS-SD name for cache lookup. Lower-cases,
+/// drops a trailing FQDN dot, and drops the `.local` link-local
+/// suffix. The `.local` domain is implied for everything mDNS-SD
+/// touches, so callers shouldn't have to remember whether to include
+/// it — config that says `Foo.local`, an announcer's instance label
+/// `Foo`, and an SRV target `foo.local.` all collapse to `foo`.
+pub(crate) fn normalize_mdns_name(s: &str) -> String {
+    let s = strip_trailing_dot(s);
+    let s = s.strip_suffix(".local").unwrap_or(s);
+    s.to_ascii_lowercase()
+}
+
 /// Shared `peer_hostname -> primary_ipv4` map, populated by Discovery
 /// and read by the dialer (`connect_to_handle`). Owned by the dialer
 /// path so its references survive across discovery enable/disable
@@ -313,7 +325,7 @@ fn start_browse(
                     };
                     let instance =
                         instance_from_fullname(resolved.get_fullname(), SERVICE_TYPE);
-                    let key = strip_trailing_dot(instance).to_ascii_lowercase();
+                    let key = normalize_mdns_name(instance);
                     let target = strip_trailing_dot(resolved.get_hostname());
                     log::info!(
                         "mdns: peer instance={key} (target={target}) announces primary={ip} \