fix: order collisions, task-complete undo, filing from a fresh install, and four defects

[malinfossum]

Eight commits. Every change is either a defect confirmed by reproduction or a fix you asked for directly.

The "can move up but not down" bug — confirmed, root cause found

create() set order = siblings.length. A delete leaves a hole, so the count can equal an order still in use: create three tasks (0, 1, 2), delete the middle one, and the next create takes order 2 again.

Two tasks sharing an order make swapOrder a silent no-op — swapping two equal values changes nothing — so "Move down" appears in the menu and does nothing. It also makes the sort order between the pair arbitrary, because the view and the controller sort from different sources.

Proven with a failing test before the fix:

	result
d.order after a delete-induced gap	2, colliding with c.order
list after swapOrder(c, d)	unchanged

moveToSection already used max(order)+1 with a comment explaining this exact hazard. create now does the same — in all three models: tasks, sections and areas all had it, and all three drive a Move up/down.

Note: you said moving works on your phone. The defect is real regardless — it only bites once a delete has left a gap, so a database that has never hit that state behaves fine.

Undo when a task is checked off

Completing a plain task wrote straight to the model with no feedback and no way back; only recurring tasks got a toast. Now shows "Task completed" with Undo, in the completing direction only — un-checking a task is the undo.

Undo sets completed:false explicitly rather than toggling again, because you can un-check the box by hand while the toast is still up and a second toggle would re-complete it.

Filing a task from the Focus tab

Not a bug — a design gap. "Move to…" was gated on sections.length > 1, so a fresh install (one area, one section) never saw the item at all, and the notepad's File shortcut was gated the same way. There was no route from a task to anywhere else and no hint one existed.

The picker now carries "＋ New section…", and both gates are gone. The new section is created in the task's own area, so you are never asked to pick one. Undo removes the created section as well as moving the task back, so it is a complete reversal rather than a partial one.

Four more defects from the backlog

• Toast "Undo" that did nothing — every toast rendered the button, including those passing no onAction, so clicking it merely dismissed and told you a reversal had happened when none had.
• Three in-flight races — capture and the section add row both held their text across an awaited write, so a fast double-Enter created duplicate tasks; onCycleTheme read a value the write only updates afterwards, so two fast clicks skipped a cycle step.
• Next hero misaligned — .next-card's own inline padding nested inside .task's, putting the hero row 16px in from both edges relative to every group row.
• Heading levels skipped — group headings were <h3> under the page <h1>; the Next card's <h2> bridged it on Today, but the other three tabs had no bridge.

Verified

• 251 tests pass (was 247; +4 regression tests), biome check . clean, npm run build clean, no console errors
• Move-down: failing tests written first, then fixed
• Undo on complete: full cycle in the browser — completed 0 → 1, row disappears, toast; Undo → completed 0, row returns
• New section: 1 section → create → 2 sections + task moved → Undo → 1 section + task back
• Alignment: left, right, title and star edges all match the group rows exactly at 375px and 1280px, no horizontal scroll
• Theme: two same-tick clicks advance two steps

Not covered

A real-device pass is still owed and I can't do it — the in-app browser is desktop Chromium at a resized viewport. Worth noting that a CDP click landing dead centre on the 16px checkbox did not fire the handler, while a scripted click did; that's the same tool limitation already recorded for Enter, not an app bug, but it means touch behaviour here is unverified.