fix: Paket 0 – data integrity, security hardening and field usability

Backend
- Backup covers every Prisma model (bundle v3); a guard test fails for any
  new model that is neither backed up nor explicitly excluded. Unsealed
  bundles may only add rows to 27 legacy master/field tables and never
  overwrite; counters, ledgers, settings, roles etc. need a sealed file.
  Shared import limit BACKUP_MAX_IMPORT_BYTES (default 50 MB, max 256 MB)
  with warnings in log and UI; replaced document files are removed after
  commit.
- Post-commit side effects (automation, calendar sync, webhooks) run via
  runAfterCommit and never turn a committed write into a 500, so retries
  with the same Idempotency-Key no longer create duplicates.
- Calendar outbox is multi-replica safe: per-entry claims with stale
  takeover, revision-based settle, new Graph event only on 404/410,
  transactionId on create, 30 s Graph timeout, URL-encoded ids, GUID
  validation for groupId, "run now" in background and resets FAILED.
- Automation tasks are deduplicated under a row lock on the rule.
- Update DTOs follow one null rule: omitted = unchanged, null clears a
  nullable field, null on a required field is a 400.
- Varroa mites/day is recomputed on correction; withdrawal status is
  checked against the harvest date (?at=), bounded colonyIds; inspection
  create is audited; updates re-enqueue calendar entries.
- Dashboard, statistics and apiary/colony guards treat WEAK, CONSPICUOUS
  and QUEENLESS colonies as living.
- Prisma errors and body-parser errors are logged without query values or
  request bodies.
- Migration 20261012100000_calendar_sync_claims; schema index name aligned
  with the existing database object.

Frontend
- Sticky save bar sticks again (no scroll container ancestors, card uses
  overflow-clip), safe-area insets, scroll-padding, FAB hidden on forms,
  sticky desktop sidebar.
- Inspections record yes / no / not checked instead of silent defaults.
- All living colonies are selectable; shared RecordSelect, EnumSelect,
  ChoiceGroup and TriStateField replace per-page copies; selects show
  names instead of ids; labels point at real controls.
- Emptied optional fields are sent as null (emptyToNull) so every field
  can be cleared; dates default to the local day and are sent via
  toApiDate.
- Harvest withdrawal warning uses the harvest date; backup page warns when
  a backup outgrows the import limit and lists skipped tables.

Build and docs
- Docker builds fail unless lint, typecheck and unit tests pass.
- ARCHITECTURE.md updated (assumptions 9-12, 19-21, section 8) and spec
  docs/superpowers/specs/2026-10-12-plattform-rueckgrat-und-fahrplan-design.md
  for the backbone (api/worker/job roles, domain event outbox) and the
  feature roadmap T3-T7.

Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>

ApiCore-Frontend/src/lib/dates.ts

@@ -0,0 +1,37 @@
+/**
+ * The calendar day the beekeeper sees on their phone, as "YYYY-MM-DD".
+ *
+ * Not `toISOString().slice(0, 10)`: that is the UTC day, which in Germany is
+ * still yesterday until 01:00 (winter) or 02:00 (summer) - a form opened
+ * shortly after midnight would prefill the wrong date.
+ */
+export function toLocalIsoDate(date: Date): string {
+  const year = String(date.getFullYear()).padStart(4, "0");
+  const month = String(date.getMonth() + 1).padStart(2, "0");
+  const day = String(date.getDate()).padStart(2, "0");
+  return `${year}-${month}-${day}`;
+}
+
+/** Today's local calendar day, e.g. the default date of a new record. */
+export function todayLocalIsoDate(): string {
+  return toLocalIsoDate(new Date());
+}
+
+const CALENDAR_DAY = /^\d{4}-\d{2}-\d{2}$/;
+
+/**
+ * A day picked in a date field ("YYYY-MM-DD") as the API stores calendar
+ * days: midnight UTC of exactly that day, whatever the phone's time zone.
+ * Throws on anything that is not a real calendar day rather than sending a
+ * shifted or invalid date.
+ */
+export function toApiDate(calendarDay: string): string {
+  if (!CALENDAR_DAY.test(calendarDay)) {
+    throw new RangeError(`Kein Kalendertag: "${calendarDay}"`);
+  }
+  const iso = new Date(`${calendarDay}T00:00:00.000Z`).toISOString();
+  if (iso.slice(0, 10) !== calendarDay) {
+    throw new RangeError(`Kein Kalendertag: "${calendarDay}"`);
+  }
+  return iso;
+}