feat(runtime): per-page default Period via daterange "default"

[lukaisailovic]

What

Page-level daterange filters can now declare a default period. Until now every page opened on All time with no way to set a per-page default.

A daterange filter gains an optional default:

{ "id": "period", "type": "daterange", "label": "Period",
  "bind": { "transactions": "ts" }, "default": "last-90-days" }

One of today, last-7-days, last-30-days, last-90-days, this-month, last-month — the same set already offered by the date-range control's presets.

Behavior

• When the URL sets no range, the page opens on the default, resolved live against today so it never goes stale (last-90-days always means the last 90 days from now).
• An explicit ?from=&to= still wins — the default only fills the gap.
• Omitting default keeps the current all-time behavior.
• The header reset (X) clears the URL range, which re-resolves to the page's default (reset = back to default, by design).

How

Preset math is hoisted out of PageFilters into the shared runtime/src/client/pageFilters.ts (PERIOD_PRESETS, presetBounds, defaultRangeBounds) so the route and the control build ranges from one source — the control's UI is unchanged. The route resolves the default in PageView when from/to are absent; validateSearch (and the URL shape) is untouched.

The keystone schema change in @openislands/schema regenerates types + JSON Schema; CLI/runtime/MCP follow.

Dogfood

Finance template holdings page defaults to last-90-days (daily transaction data).

Verified

• pnpm build, pnpm typecheck, pnpm test (389/389), pnpm lint, pnpm validate:templates — all green.
• New unit tests for presetBounds + defaultRangeBounds.
• SSR-checked the served finance app (today 2026-06-25): holdings → Mar 28 – Jun 25, 2026; overview (no default) → All time; holdings?from=2026-01-01&to=2026-01-31 → Jan 1 – Jan 31, 2026.

Docs

Updated docs/data-app-model.md, apps/docs/.../reference/manifest.mdx, and concepts/manifest.mdx.