jobs: run script tasks as background jobs via executeScript (phase 1b)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs/jobs-unification.md

@@ -58,9 +58,12 @@ Favor power-user affordances over guardrails. See memory `sole-user-assume-compe
 - One `notifyJobDone(job)` hook at finalize → push to the phone app.
 
 ## Progress
-- [ ] 1a data model (migration + schema/types)
-- [ ] 1b executeScript + manager dispatch
-- [ ] 1c scheduler / queue
+- [x] 1a data model — `mode` + `exit_code` columns (schema + applied to DB)
+- [x] 1b executeScript + manager dispatch — `execute-script.ts` (spawn/sandbox/killTree port, log file,
+      abort poll, returns exitCode), `process-tree.ts` (shared killTree), `pipeline-job-manager` now
+      dispatches by `mode` and finalizes script jobs by exit code. *Compiles; runtime-untested until
+      a REST caller + restart exist.*
+- [ ] 1c scheduler / queue (FIFO pending → promote on finalize; promoteNext on startup)
 - [ ] 2 REST job API + WS consolidation
 - [ ] 3 /jobs/new page + JobDetail script branch + retire modal + header indicator
 - [ ] 4 push notifications