feat: p2 batch 28-31 reminders lists comments bang stats

Calendar events support multiple reminder offsets with presets and per-user defaults.

Lists index adds inline task entry and list property editing.

Generic entity comments on list detail. New bangs.stats dashboard widget.

Closes Gitea #28, #29, #30, #31. Migrations 0022 and 0023.

src/lib/reminder-offsets.ts

@@ -0,0 +1,62 @@
+export type ReminderOffsetUnit = "minutes" | "hours" | "days" | "weeks";
+
+export type ReminderPreset = {
+  label: string;
+  offsetMinutes: number;
+};
+
+export const REMINDER_PRESETS: ReminderPreset[] = [
+  { label: "At event time", offsetMinutes: 0 },
+  { label: "5 minutes before", offsetMinutes: 5 },
+  { label: "15 minutes before", offsetMinutes: 15 },
+  { label: "30 minutes before", offsetMinutes: 30 },
+  { label: "1 hour before", offsetMinutes: 60 },
+  { label: "2 hours before", offsetMinutes: 120 },
+  { label: "1 day before", offsetMinutes: 1440 },
+  { label: "2 days before", offsetMinutes: 2880 },
+  { label: "1 week before", offsetMinutes: 10080 },
+];
+
+export function formatReminderOffset(offsetMinutes: number): string {
+  const preset = REMINDER_PRESETS.find((p) => p.offsetMinutes === offsetMinutes);
+  if (preset) return preset.label;
+
+  if (offsetMinutes === 0) return "At event time";
+  if (offsetMinutes % 10080 === 0) {
+    const weeks = offsetMinutes / 10080;
+    return weeks === 1 ? "1 week before" : `${weeks} weeks before`;
+  }
+  if (offsetMinutes % 1440 === 0) {
+    const days = offsetMinutes / 1440;
+    return days === 1 ? "1 day before" : `${days} days before`;
+  }
+  if (offsetMinutes % 60 === 0) {
+    const hours = offsetMinutes / 60;
+    return hours === 1 ? "1 hour before" : `${hours} hours before`;
+  }
+  return offsetMinutes === 1 ? "1 minute before" : `${offsetMinutes} minutes before`;
+}
+
+export function customOffsetToMinutes(value: number, unit: ReminderOffsetUnit): number {
+  const safe = Math.max(0, Math.floor(value));
+  switch (unit) {
+    case "minutes":
+      return safe;
+    case "hours":
+      return safe * 60;
+    case "days":
+      return safe * 1440;
+    case "weeks":
+      return safe * 10080;
+  }
+}
+
+export function normalizeReminderOffsets(offsets: number[]): number[] {
+  return [...new Set(offsets.filter((n) => Number.isFinite(n) && n >= 0))].toSorted(
+    (a, b) => b - a,
+  );
+}
+
+export function fireAtForEventStart(startAt: Date, offsetMinutes: number): Date {
+  return new Date(startAt.getTime() - offsetMinutes * 60_000);
+}