feat(playbooks): launch steps with pinned persona snapshots

[BastiHu]

Playbook steps need stable persona definitions and model routes throughout a run.

Bind the required personas when execution starts, save immutable snapshots, and let thread launch consume the prepared assignments without silently rerouting them.

Stack 1/9. Based on j5/main. Merge in order, retargeting to j5/main as predecessors land. Full-stack testing branch: codex/playbooks-09-aurora-loops.

Validation at the integrated stack tip: 179 server/shared tests and 104 web tests passed; server and web typechecks passed. Each regenerated runtime manifest was checked. The adapter slice independently passed 92 tests, including the parser regressions.

Review order:

1. 01-persona-launch
2. 02-engine
3. 03-adapters
4. 04-yaml-library
5. 05-runtime-api
6. 06-client-state
7. 07-run-ui
8. 08-authoring
9. 09-aurora-loops

Model: GPT-5 · Harness: Codex

[Jacksondr5]

Requesting changes: the stack edits upstream-owned files without recording a single FORK.md case.

FORK.md ("Add, don't modify") and docs/j5/process/working-in-the-repo.md require every edit to an upstream-owned file to be an appended integration case that is enumerated in the FORK.md inventory. This stack leaves FORK.md byte-identical while touching the files below. That is the blocker for the whole stack, since each later PR merges through this one.

Upstream-owned files touched, by PR:

PR	File	Shape of the edit
#156	apps/server/src/orchestration-v2/ThreadLaunchService.ts	Appended optional input field. Needs an inventory case.
#157	apps/server/package.json, pnpm-lock.yaml	Workspace dependency append. Note in the case.
#158	apps/server/src/orchestration-v2/RestartContinuation.ts + test	Two early returns inserted into upstream function bodies. This file is already listed under "Temporary in-place patches" to be re-evaluated at the next upstream merge; adding more J5 logic there raises that tax. Needs a case and a stated exit plan, or a different mechanism.
#159	apps/server/scripts/copy-playbook-yaml.mjs	New J5-only file placed under an upstream directory. Move under a j5/ path.
#160	apps/server/src/persistence/Layers/Sqlite.ts	Appended migration call in the fork-owned lane. Fine in shape, needs a case.
#160	apps/server/package.json (build:bundle)	Inserts a manifest check and a copy step into upstream's build script. Needs a case, or move the steps to a J5-owned script that wraps the upstream one.
#162	apps/web/src/components/ChatView.tsx, RightPanelTabs.tsx, Sidebar.tsx, LegacySidebar.tsx, routes/_chat.$environmentId.$threadId.tsx, routes/_chat.pull-requests.tsx	Appended surface wiring, acceptable shape, needs a case. Two upstream strings were rewritten for no functional reason (the "workflow runs" comment in ChatView and the Agents card description); revert those.
#162	apps/web/src/rightPanelStore.ts	Beyond an appended case: rewrites the persisted-state migration filter and bumps the storage version to 13, which upstream will also use. Keep the append, drop the rewrite, or justify it in the case.
#162	apps/web/src/components/sidebar/SidebarChrome.tsx	Beyond an appended case: changes the environment pill breakpoint and removes shrink-0 on the brand for every user. Isolate the new button so existing layout rules stay untouched.
#163	apps/web/src/components/settings/SettingsSidebarNav.tsx, settingsSearch.ts, routes/settings.playbooks.tsx	Appended entries, needs a case.
#163	apps/web/src/hooks/useHandleNewThread.test.ts	+105 lines importing J5 code into an upstream test file. Move these tests to the J5-owned CreatePlaybookLauncher.logic.test.ts.
#164	apps/server/src/j5/agents/agentPersonaProviderPolicy.ts, agentPersonaRuntime.ts	J5-owned, so not a fork violation, but note that #164 changes diagnostic authority globally, not only for playbooks. Call that out in the PR body.

What would unblock this:

1. Add one numbered FORK.md case (or a small group) for the Playbooks integration seams, naming the symbols and tests as the existing cases do.
2. Reduce the four edits marked "beyond an appended case" to appends, or record the justification for each in the case.
3. Move the copy script and the build-step additions into J5-owned locations.
4. Move the J5 tests out of the upstream test file.

The runtime and correctness findings from the review are posted separately and are not part of this block.

Reviewed by Claude Fable 5.1 (Claude Code) with GPT-6-Astra (Codex) on the server slices.