ask_operator: ttl_seconds auto-cancel + remaining-time chip

manager can pass ttl_seconds to ask_operator. on submit, host
stores deadline_at = now + ttl in operator_questions (new column,
migrated via existing pragma_table_info pattern), spawns a tokio
task that sleeps until the deadline then resolves the question with
answer '[expired]' and fires the same OperatorAnswered helper event.
already-resolved races no-op silently.

dashboard renders a '⏳ MM:SS' chip on the question row when
deadline_at is set. format collapses seconds → s, < 1h → m s, ≥ 1h
→ h m. heartbeat refresh (5s) keeps the chip current; the operator
sees it tick down.

manager prompt + mcp tool description updated. journald viewer per
container queued in todo (separate task).

hive-c0re/src/operator_questions.rs

@@ -25,17 +25,29 @@ CREATE INDEX IF NOT EXISTS idx_operator_questions_pending
     ON operator_questions (id) WHERE answered_at IS NULL;
 ";
 
-/// Add the `multi` column to pre-existing databases. `ALTER TABLE ADD COLUMN`
-/// has no `IF NOT EXISTS` form in sqlite, so we check `pragma_table_info` first.
-fn ensure_multi_column(conn: &Connection) -> Result<()> {
-    let has: bool = conn
-        .prepare("SELECT 1 FROM pragma_table_info('operator_questions') WHERE name = 'multi'")?
-        .exists([])?;
-    if !has {
-        conn.execute_batch(
+/// Add late-added columns to pre-existing databases. `ALTER TABLE
+/// ADD COLUMN` has no `IF NOT EXISTS` form in sqlite, so we check
+/// `pragma_table_info` first per column.
+fn ensure_columns(conn: &Connection) -> Result<()> {
+    for (name, sql) in [
+        (
+            "multi",
             "ALTER TABLE operator_questions ADD COLUMN multi INTEGER NOT NULL DEFAULT 0;",
-        )
-        .context("add operator_questions.multi column")?;
+        ),
+        (
+            "deadline_at",
+            "ALTER TABLE operator_questions ADD COLUMN deadline_at INTEGER;",
+        ),
+    ] {
+        let has: bool = conn
+            .prepare(&format!(
+                "SELECT 1 FROM pragma_table_info('operator_questions') WHERE name = '{name}'"
+            ))?
+            .exists([])?;
+        if !has {
+            conn.execute_batch(sql)
+                .with_context(|| format!("add operator_questions.{name} column"))?;
+        }
     }
     Ok(())
 }
@@ -49,6 +61,10 @@ pub struct OpQuestion {
     pub options: Vec<String>,
     pub multi: bool,
     pub asked_at: i64,
+    /// Absolute unix-seconds deadline after which a watchdog auto-
+    /// resolves the question with answer `[expired]`. `None` = no
+    /// expiry. Surfaced on the dashboard as a remaining-time chip.
+    pub deadline_at: Option<i64>,
     pub answered_at: Option<i64>,
     pub answer: Option<String>,
 }
@@ -68,7 +84,7 @@ impl OperatorQuestions {
             .with_context(|| format!("open operator_questions db {}", path.display()))?;
         conn.execute_batch(SCHEMA)
             .context("apply operator_questions schema")?;
-        ensure_multi_column(&conn).context("migrate operator_questions.multi")?;
+        ensure_columns(&conn).context("migrate operator_questions columns")?;
         Ok(Self {
             conn: Mutex::new(conn),
         })
@@ -80,13 +96,22 @@ impl OperatorQuestions {
         question: &str,
         options: &[String],
         multi: bool,
+        deadline_at: Option<i64>,
     ) -> Result<i64> {
         let conn = self.conn.lock().unwrap();
         let options_json = serde_json::to_string(options).unwrap_or_else(|_| "[]".into());
         conn.execute(
-            "INSERT INTO operator_questions (asker, question, options_json, multi, asked_at)
-             VALUES (?1, ?2, ?3, ?4, ?5)",
-            params![asker, question, options_json, i64::from(multi), now_unix()],
+            "INSERT INTO operator_questions
+               (asker, question, options_json, multi, deadline_at, asked_at)
+             VALUES (?1, ?2, ?3, ?4, ?5, ?6)",
+            params![
+                asker,
+                question,
+                options_json,
+                i64::from(multi),
+                deadline_at,
+                now_unix(),
+            ],
         )?;
         Ok(conn.last_insert_rowid())
     }
@@ -119,7 +144,7 @@ impl OperatorQuestions {
     pub fn get(&self, id: i64) -> Result<Option<OpQuestion>> {
         let conn = self.conn.lock().unwrap();
         conn.query_row(
-            "SELECT id, asker, question, options_json, multi, asked_at, answered_at, answer
+            "SELECT id, asker, question, options_json, multi, asked_at, answered_at, answer, deadline_at
                FROM operator_questions WHERE id = ?1",
             params![id],
             row_to_question,
@@ -131,7 +156,7 @@ impl OperatorQuestions {
     pub fn pending(&self) -> Result<Vec<OpQuestion>> {
         let conn = self.conn.lock().unwrap();
         let mut stmt = conn.prepare(
-            "SELECT id, asker, question, options_json, multi, asked_at, answered_at, answer
+            "SELECT id, asker, question, options_json, multi, asked_at, answered_at, answer, deadline_at
                FROM operator_questions
               WHERE answered_at IS NULL
               ORDER BY id ASC",
@@ -155,6 +180,7 @@ fn row_to_question(row: &rusqlite::Row<'_>) -> rusqlite::Result<OpQuestion> {
         asked_at: row.get(5)?,
         answered_at: row.get(6)?,
         answer: row.get(7)?,
+        deadline_at: row.get(8)?,
     })
 }