dashboard: K3PT ST4T3 section + agent links open in new tab

new section between containers and questions: lists every name with a
state dir under /var/lib/hyperhive/agents/ that doesn't correspond to
a live container. shows state size + last-modified age + whether
claude creds are kept. two actions per row:

- R3V1V3 — queues a spawn approval with the same name (operator
  approves to recreate; spawn flow reuses prior config + claude
  creds, no re-login needed)
- PURG3 — wipes the agent's state + applied dirs (post /purge-tombstone/
  endpoint; refuses if a live container with that name still exists)

dashboard also opens agent links in new tabs now (target=_blank +
rel=noopener) so the operator's overview tab stays put when they
dive into an agent.

hive-c0re/src/operator_questions.rs

@@ -26,7 +26,7 @@ CREATE INDEX IF NOT EXISTS idx_operator_questions_pending
 ";
 
 /// 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.
+/// 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'")?