Tie each hook to a session, picked in the hook form

A hook's calls used to run in whatever session was active at the time.
Now `bot_hooks.session_id` pins them to one session, open or closed
(null still follows the active one). The hook form picks where it runs
(the bot's own chat or one of its workspaces) and a session there, or a
new one of its own started beside the active one so the chat on screen
stays. A bot's proposed hook gets the session it was proposed in, and a
missing session is replaced on the next call. Changing place or session
is refused while a run is open; the computer stays only if reachable.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/functions/backend/db/hook-proposals/confirm-hook-proposal.ts

@@ -16,7 +16,8 @@ type Params = {
  * The user confirmed a hook proposal from its card: claims it (once, and
  * only while it's pending and not expired), checks it again against the
  * hook and the bot's reach now, then saves it with the Hooks modal's own
- * helpers, as that user. Returns the proposal and, for a new hook called
+ * helpers, as that user. A new hook runs in the session it was proposed
+ * in (a new one of its own if that's gone). Returns the proposal and, for a new hook called
  * at a URL, its token: the card shows it this once, and it's never
  * stored in the outcome, which the bot is told. Whatever happens is
  * recorded on the proposal as its `outcome`.
@@ -46,6 +47,8 @@ export default async function confirmHookProposal({ user_id, proposal_id }: Para
                 user_id,
                 bot_id: proposal.bot_id,
                 workspace_id: proposal.workspace_id,
+                session: proposal.session_id ? Number(proposal.session_id) : "current",
+                session_missing_starts_new: true,
                 title: data.title!,
                 instructions: data.instructions!,
                 computer_id: data.computer_id,