feat(lifeboard): a Packs screen, and authoring one by describing it

[ivanmkc]

The stack

#	PR	What it adds	Tests at this point
1	#311	A real localStorage for the test suite on Node 25	viewer 747
2	#312	@ivanmkc/termchart-canvas; injectable interact transport	canvas 473 · viewer 278
3	#313	lifeboard PWA: fact log, boards, service worker	lifeboard 36
4	#314	Shell, family profiles, tap layer	lifeboard 82
5	#315	The agent turn, four providers, Connections	lifeboard 142
6	#316	Packs, recipes, shopping-list arithmetic	lifeboard 231
7	#317	Provenance and lineage	lifeboard 257
8	#318	Calendar, Gmail, mail triage	lifeboard 301
9	#319	The bridge and long jobs	cli 314 · lifeboard 320
10	#310	Proactivity, scheduled boards, Google sign-in	cli 320 · lifeboard 343
11	#320	Persistence audit fixes: multi-tab, stale builds, no-storage boot	lifeboard 350
12	#321	User guide, bridge setup, QA guide, persistence audit	lifeboard 350
13	#322	A plan for third-party integrations (docs only)	unchanged
14	#323	A practice drill a board can define: audio + Q&A	canvas 485 · lifeboard 372
15	#325	Export and restore	lifeboard 389
16	#326	Draft a message, approve it, then send	lifeboard 399
17	#327	Hand long work to the Mac	lifeboard 406
18	#328	A Packs screen, and authoring one by describing it	lifeboard 418
19	#329	Activity — what changed, who changed it, undo	lifeboard 428

Every branch in the stack was checked out on its own and verified independently: npm install, tsc --noEmit for every package, npm test across the workspace, and the offline e2e where it exists. All nineteen are green — no branch depends on a later one to build or pass. Full viewer e2e (11 suites, 106 assertions) was run on #312 as the behaviour-preservation evidence for the extraction.

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Stack position: 18 of 19. Base: lifeboard/16-jobs-ui.

The last of the four capabilities that were built, tested and unreachable. draftPack, refinePack and installPack have worked since the pack system landed; there was no screen.

Furniture rather than a board, for the reason Connections is: what gets typed here decides what goes into the assistant's prompt on every later turn, and the agent must not be able to redraw that screen.

The loop is draft → preview → refine → save, and the save is explicit. A preview that silently became real would be a stranger's JSON in the prompt of every turn afterwards. Going back one revision works, because refinement often makes things worse. Editing a built-in pack forks a copy, so a bad edit cannot break a board that was working a second ago.

The library states, per pack, what it may write and what it triggers on — the authorisation boundary in words rather than buried in JSON — and says that packs are data, not code, because that is the property a person is being asked to trust.

Verified: lifeboard 418 (+12), including that a pack asking for a shell capability is refused with the reason.