fix: replace bash_tasks.rs with generic mcp_loose_ends scanner

- hive-ag3nt: remove bash_tasks.rs entirely; add mcp_loose_ends.rs that
  scans harness/mcp-loose-ends/*.json generically (no bash knowledge)
- hive-bash-mcp: daemon writes mcp-loose-ends/bash.json on every task
  state transition (pending/running/done/interrupted/timed_out)
- get_loose_ends: reads mcp_loose_ends::collect() instead of bash-specific code
- implements the generic mechanism from #1162

hive-bash-mcp/src/runner.rs

@@ -84,6 +84,42 @@ pub fn read_task(id: &str) -> Option<TaskFile> {
     serde_json::from_str(&s).ok()
 }
 
+// ---------------------------------------------------------------------------
+// Loose-ends file (generic MCP loose-ends protocol)
+// ---------------------------------------------------------------------------
+
+/// Rewrite `mcp-loose-ends/bash.json` with a summary of all currently
+/// active (Pending or Running) tasks. The harness scans this directory
+/// generically in `get_loose_ends` — no bash-specific code needed there.
+///
+/// File format: a JSON array of plain-text summary strings, one per
+/// loose-end item. The harness includes them verbatim in the output.
+/// Atomic write (tmp + rename) so the harness never reads a partial file.
+fn refresh_loose_ends() {
+    let active = active_tasks();
+    let dir = paths::mcp_loose_ends_dir();
+    if let Err(e) = std::fs::create_dir_all(&dir) {
+        tracing::warn!(error = ?e, "bash_runner: create mcp-loose-ends dir failed");
+        return;
+    }
+    let items: Vec<String> = active
+        .iter()
+        .map(|t| {
+            let age = now_unix() - t.created_at;
+            format!(
+                "bash task `{}` status={:?}, cmd: `{}`, age {}s",
+                t.id, t.status, t.cmd, age
+            )
+        })
+        .collect();
+    let dest = dir.join("bash.json");
+    let tmp = dest.with_extension("json.tmp");
+    let json = serde_json::to_string(&items).unwrap_or_else(|_| "[]".to_owned());
+    if let Err(e) = std::fs::write(&tmp, &json).and_then(|_| std::fs::rename(&tmp, &dest)) {
+        tracing::warn!(error = ?e, "bash_runner: write mcp-loose-ends/bash.json failed");
+    }
+}
+
 // ---------------------------------------------------------------------------
 // Public API used by daemon dispatch
 // ---------------------------------------------------------------------------
@@ -110,6 +146,7 @@ pub fn submit_task(cmd: String, timeout_secs: Option<u64>) -> Result<String> {
         stderr_tail: None,
     };
     write_task(&task)?;
+    refresh_loose_ends();
     Ok(id)
 }
 
@@ -216,6 +253,7 @@ async fn mark_interrupted(socket: &Path) {
         if let Err(e) = write_task(&task) {
             tracing::warn!(id = %id, error = ?e, "bash_runner: write interrupted state failed");
         }
+        refresh_loose_ends();
         send_wake(socket, &id, "interrupted (daemon restarted)", None).await;
     }
 }
@@ -266,6 +304,7 @@ async fn run_task(mut task: TaskFile, socket: &Path) {
     if let Err(e) = write_task(&task) {
         tracing::warn!(id = %id, error = ?e, "bash_runner: write running state failed");
     }
+    refresh_loose_ends();
 
     let out_path = paths::task_out(&id);
     let err_path = paths::task_err(&id);
@@ -299,6 +338,7 @@ async fn run_task(mut task: TaskFile, socket: &Path) {
     if let Err(e) = write_task(&task) {
         tracing::warn!(id = %id, error = ?e, "bash_runner: write done state failed");
     }
+    refresh_loose_ends();
 
     let summary = if timed_out {
         format!("timed out after {}s", task.timeout_secs)