Fix bail script: pass own pid file so it can exclude itself

The bail-no-competing.sh script expects $1 to be the path to the
current agent's pid file so it can skip it when checking for
competing processes. But the runner wasn't passing any arguments,
so $1 was empty and the script treated every pid file (including
the agent's own) as a competing process — bailing every time.

This caused surface-observe to always bail at step 2, preventing
all memory graph maintenance (organize, observe phases) from
running.

Co-Authored-By: Proof of Concept <poc@bcachefs.org>

src/agent/oneshot.rs

@@ -474,9 +474,13 @@ pub fn run_one_agent(
     // Bail check: if the agent defines a bail script, run it between steps.
     let bail_script = def.bail.as_ref().map(|name| defs::agents_dir().join(name));
     let state_dir_for_bail = state_dir.clone();
+    // Find our own pid file so we can pass it to the bail script
+    let our_pid = std::process::id();
+    let our_pid_file = format!("pid-{}", our_pid);
     let bail_fn = move |step_idx: usize| -> Result<(), String> {
         if let Some(ref script) = bail_script {
             let status = std::process::Command::new(script)
+                .arg(&our_pid_file)
                 .current_dir(&state_dir_for_bail)
                 .status()
                 .map_err(|e| format!("bail script {:?} failed: {}", script, e))?;