feat: Function triggers — schedule, inbound hook, domain events

Migration 00016: function_id on scheduled_jobs/inbound_hooks,
event_pattern on functions, 'event' in the run-trigger enum.

- Jobs deliver to a function instead of HTTP when function_id is set;
  the run's status_code mirrors the process exit code. Clearing the
  field returns the job to URL delivery.
- Inbound hooks gain mode "function" — received body becomes stdin
  payload, acked immediately, run recorded async.
- event_pattern (document.*, *, exact type) fires the function detached
  on matching publishEvent — never blocks realtime/webhook fan-out.
- One executeFunction path serves manual/schedule/hook/event; run rows
  record the trigger source.
- Backend image now ships bun 1.3.14 so Functions work under compose.

Dashboard: job target picker, hook function mode, event-pattern field.

Verified live: job run → success (status_code 0), hook POST → run,
document.created → event run with correct payload.

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

apps/backend/db/queries/functions.sql

@@ -1,6 +1,6 @@
 -- name: CreateFunction :one
-INSERT INTO core.functions (project_id, name, code, runtime)
-VALUES ($1, $2, $3, $4)
+INSERT INTO core.functions (project_id, name, code, runtime, event_pattern)
+VALUES ($1, $2, $3, $4, $5)
 RETURNING *;
 
 -- name: GetFunction :one
@@ -18,6 +18,7 @@ ORDER BY name;
 UPDATE core.functions
 SET code = COALESCE(sqlc.narg('code'), code),
     enabled = COALESCE(sqlc.narg('enabled'), enabled),
+    event_pattern = COALESCE(sqlc.narg('event_pattern'), event_pattern),
     updated_at = NOW()
 WHERE id = $1 AND project_id = $2
 RETURNING *;
@@ -35,3 +36,10 @@ SELECT * FROM core.function_runs
 WHERE function_id = $1
 ORDER BY created_at DESC
 LIMIT $2;
+
+-- name: ListFunctionsForEvent :many
+SELECT * FROM core.functions
+WHERE project_id = $1
+  AND enabled = TRUE
+  AND event_pattern <> ''
+  AND ($2 LIKE REPLACE(event_pattern, '*', '%') OR event_pattern = '*');