rebuild the status model as herdr's state machine, event-driven and tested

the seen logic was inverted: first observations were marked done and real
completions idle, so the menu showed teal for agents that did nothing and
green for agents that finished, and attending changed nothing visible.

- watcher::advance is herdr's apply_pane_state_change + mark_active_tab_seen
  as a pure function, unit-tested against herdr's own cases; attendance is
  window-level like herdr's active tab
- hook reports are events applied in order, so a turn shorter than a poll is
  still a completion
- event-driven: hook reports, dingger focus, and tmux focus hooks wake the
  watcher; notifications are delivered off-thread (the macos call blocked
  ticks for 2+ seconds) after the pane options are written
- all per-pane state persists in tmux pane options, so restarts and deploys
  lose nothing, including the authoritative hook state
- every click goes through dingger focus: the menu bar shells out to it and
  the status-line binding runs it; it picks the right client, skips the
  window already shown, and activates the terminal app hosting the client
- the ready queue is ordered like the menu (blocked first, then oldest done)
- menu bar and tmux segment render herdr's symbols in herdr's palette
- tests/e2e.sh: 60 assertions against an isolated tmux server with a real
  client, a 30s poll interval, and a slow fake notifier

1 files changed, 22 insertions, 9 deletions

diff --git a/crates/dinggerd/src/notify.rs b/crates/dinggerd/src/notify.rs
index 9fcfcde..e619d6d 100644
--- a/crates/dinggerd/src/notify.rs
+++ b/crates/dinggerd/src/notify.rs
@@ -3,7 +3,7 @@
 use std::process::{Command, Stdio};
 use std::sync::atomic::{AtomicU64, Ordering};
 
-use tracing::{debug, warn};
+use tracing::{info, warn};
 
 pub enum NotificationKind {
     NeedsAttention,
@@ -63,14 +63,27 @@ pub fn play_sound(kind: &NotificationKind) {
     }
 }
 
+/// Deliver a macOS notification without blocking the caller: the delivery
+/// call waits on Notification Center for seconds, and the watcher must keep
+/// updating the UI meanwhile.
 pub fn send_notification(agent_label: &str, kind: &NotificationKind, context: &str) {
-    debug!(agent = agent_label, kind = kind.title(), context, "notifying");
+    info!(agent = agent_label, kind = kind.title(), context, "notifying");
     let title = format!("{agent_label} {}", kind.title());
-    let notification = mac_notification_sys::Notification::new()
-        .title(title.as_str())
-        .message(context)
-        .send();
-    if let Err(err) = notification {
-        warn!(%err, "failed to deliver macOS notification");
-    }
+    let context = context.to_string();
+    std::thread::spawn(move || {
+        // Test seam: deliver through a command instead (tests/e2e.sh).
+        if let Ok(command) = std::env::var("DINGGER_NOTIFIER") {
+            let _ = std::process::Command::new("sh")
+                .args(["-c", &command, &title, &context])
+                .status();
+            return;
+        }
+        let notification = mac_notification_sys::Notification::new()
+            .title(title.as_str())
+            .message(context.as_str())
+            .send();
+        if let Err(err) = notification {
+            warn!(%err, "failed to deliver macOS notification");
+        }
+    });
 }