Add public/private calendars, full iCal support, and iCal URL import

- Public/private: toggle is_public via PUT /calendars/{id}; generate/clear
  public_token and return ical_url when public
- Public feed: GET /cal/{token}/feed.ics (no auth) for subscription in
  Google/Apple/Outlook calendars
- Full iCal export: use golang-ical; VALARM, ATTENDEE, all-day (VALUE=DATE),
  RRULE, DTSTAMP, CREATED, LAST-MODIFIED
- Full iCal import: parse TZID, VALUE=DATE, VALARM, ATTENDEE, RRULE
- Import from URL: POST /calendars/import-url with calendar_id + url
- Migration: unique index on public_token, calendar_subscriptions table
- Config: BASE_URL for ical_url; Calendar model + API: ical_url field
- Docs: OpenAPI, llms.txt, README, SKILL.md, about/overview

Made-with: Cursor

internal/repository/subscriptions.sql.go

@@ -0,0 +1,55 @@
+// Code generated by sqlc. DO NOT EDIT.
+// versions:
+//   sqlc v1.30.0
+// source: subscriptions.sql
+
+package repository
+
+import (
+	"context"
+
+	"github.com/jackc/pgx/v5/pgtype"
+)
+
+const createCalendarSubscription = `-- name: CreateCalendarSubscription :one
+INSERT INTO calendar_subscriptions (id, calendar_id, source_url)
+VALUES ($1, $2, $3)
+RETURNING id, calendar_id, source_url, last_synced_at, created_at
+`
+
+type CreateCalendarSubscriptionParams struct {
+	ID         pgtype.UUID `json:"id"`
+	CalendarID pgtype.UUID `json:"calendar_id"`
+	SourceUrl  string      `json:"source_url"`
+}
+
+func (q *Queries) CreateCalendarSubscription(ctx context.Context, arg CreateCalendarSubscriptionParams) (CalendarSubscription, error) {
+	row := q.db.QueryRow(ctx, createCalendarSubscription, arg.ID, arg.CalendarID, arg.SourceUrl)
+	var i CalendarSubscription
+	err := row.Scan(
+		&i.ID,
+		&i.CalendarID,
+		&i.SourceUrl,
+		&i.LastSyncedAt,
+		&i.CreatedAt,
+	)
+	return i, err
+}
+
+const getSubscriptionByCalendar = `-- name: GetSubscriptionByCalendar :one
+SELECT id, calendar_id, source_url, last_synced_at, created_at FROM calendar_subscriptions
+WHERE calendar_id = $1
+`
+
+func (q *Queries) GetSubscriptionByCalendar(ctx context.Context, calendarID pgtype.UUID) (CalendarSubscription, error) {
+	row := q.db.QueryRow(ctx, getSubscriptionByCalendar, calendarID)
+	var i CalendarSubscription
+	err := row.Scan(
+		&i.ID,
+		&i.CalendarID,
+		&i.SourceUrl,
+		&i.LastSyncedAt,
+		&i.CreatedAt,
+	)
+	return i, err
+}