feat(calendar): add overlapping layout and event attachments

public/locales/ar.json

@@ -358,7 +358,12 @@
       "resetToast": "تم إعادة تعيين التغييرات."
     },
     "iconLabel": "Icon",
-    "invalidDate": "Use a valid date in the selected date format."
+    "invalidDate": "Use a valid date in the selected date format.",
+    "attachmentLabel": "Attachment",
+    "attachmentHint": "Attach a local image, PDF, or document. Images will be shown in the event popup.",
+    "attachmentFallback": "Attachment",
+    "attachmentReadError": "The attachment could not be read.",
+    "attachmentTooLarge": "Attachment may be at most 5 MB."
   },
   "notes": {
     "title": "لوحة الملاحظات",

public/locales/de.json

@@ -375,7 +375,12 @@
       "resetToast": "Änderungen zurückgesetzt."
     },
     "iconLabel": "Icon",
-    "invalidDate": "Bitte ein gültiges Datum im ausgewählten Format verwenden."
+    "invalidDate": "Bitte ein gültiges Datum im ausgewählten Format verwenden.",
+    "attachmentLabel": "Attachment",
+    "attachmentHint": "Attach a local image, PDF, or document. Images will be shown in the event popup.",
+    "attachmentFallback": "Attachment",
+    "attachmentReadError": "The attachment could not be read.",
+    "attachmentTooLarge": "Attachment may be at most 5 MB."
   },
   "notes": {
     "title": "Notizen",

public/locales/el.json

@@ -358,7 +358,12 @@
       "resetToast": "Οι αλλαγές επαναφέρθηκαν."
     },
     "iconLabel": "Icon",
-    "invalidDate": "Use a valid date in the selected date format."
+    "invalidDate": "Use a valid date in the selected date format.",
+    "attachmentLabel": "Attachment",
+    "attachmentHint": "Attach a local image, PDF, or document. Images will be shown in the event popup.",
+    "attachmentFallback": "Attachment",
+    "attachmentReadError": "The attachment could not be read.",
+    "attachmentTooLarge": "Attachment may be at most 5 MB."
   },
   "notes": {
     "title": "Σημειώσεις",

public/locales/en.json

@@ -358,7 +358,12 @@
       "resetToast": "Changes reset."
     },
     "iconLabel": "Icon",
-    "invalidDate": "Use a valid date in the selected date format."
+    "invalidDate": "Use a valid date in the selected date format.",
+    "attachmentLabel": "Attachment",
+    "attachmentHint": "Attach a local image, PDF, or document. Images will be shown in the event popup.",
+    "attachmentFallback": "Attachment",
+    "attachmentReadError": "The attachment could not be read.",
+    "attachmentTooLarge": "Attachment may be at most 5 MB."
   },
   "notes": {
     "title": "Board",

public/locales/es.json

@@ -358,7 +358,12 @@
       "resetToast": "Cambios restablecidos."
     },
     "iconLabel": "Icon",
-    "invalidDate": "Use a valid date in the selected date format."
+    "invalidDate": "Use a valid date in the selected date format.",
+    "attachmentLabel": "Attachment",
+    "attachmentHint": "Attach a local image, PDF, or document. Images will be shown in the event popup.",
+    "attachmentFallback": "Attachment",
+    "attachmentReadError": "The attachment could not be read.",
+    "attachmentTooLarge": "Attachment may be at most 5 MB."
   },
   "notes": {
     "title": "Notas",

public/locales/fr.json

@@ -358,7 +358,12 @@
       "resetToast": "Modifications annulées."
     },
     "iconLabel": "Icon",
-    "invalidDate": "Use a valid date in the selected date format."
+    "invalidDate": "Use a valid date in the selected date format.",
+    "attachmentLabel": "Attachment",
+    "attachmentHint": "Attach a local image, PDF, or document. Images will be shown in the event popup.",
+    "attachmentFallback": "Attachment",
+    "attachmentReadError": "The attachment could not be read.",
+    "attachmentTooLarge": "Attachment may be at most 5 MB."
   },
   "notes": {
     "title": "Notes",

public/locales/hi.json

@@ -358,7 +358,12 @@
       "resetToast": "परिवर्तन रीसेट हो गए।"
     },
     "iconLabel": "Icon",
-    "invalidDate": "Use a valid date in the selected date format."
+    "invalidDate": "Use a valid date in the selected date format.",
+    "attachmentLabel": "Attachment",
+    "attachmentHint": "Attach a local image, PDF, or document. Images will be shown in the event popup.",
+    "attachmentFallback": "Attachment",
+    "attachmentReadError": "The attachment could not be read.",
+    "attachmentTooLarge": "Attachment may be at most 5 MB."
   },
   "notes": {
     "title": "नोट बोर्ड",

public/locales/it.json

@@ -358,7 +358,12 @@
       "resetToast": "Modifiche ripristinate."
     },
     "iconLabel": "Icon",
-    "invalidDate": "Use a valid date in the selected date format."
+    "invalidDate": "Use a valid date in the selected date format.",
+    "attachmentLabel": "Attachment",
+    "attachmentHint": "Attach a local image, PDF, or document. Images will be shown in the event popup.",
+    "attachmentFallback": "Attachment",
+    "attachmentReadError": "The attachment could not be read.",
+    "attachmentTooLarge": "Attachment may be at most 5 MB."
   },
   "notes": {
     "title": "Bacheca",

public/locales/ja.json

@@ -358,7 +358,12 @@
       "resetToast": "変更がリセットされました。"
     },
     "iconLabel": "Icon",
-    "invalidDate": "Use a valid date in the selected date format."
+    "invalidDate": "Use a valid date in the selected date format.",
+    "attachmentLabel": "Attachment",
+    "attachmentHint": "Attach a local image, PDF, or document. Images will be shown in the event popup.",
+    "attachmentFallback": "Attachment",
+    "attachmentReadError": "The attachment could not be read.",
+    "attachmentTooLarge": "Attachment may be at most 5 MB."
   },
   "notes": {
     "title": "メモボード",

public/locales/pt.json

@@ -358,7 +358,12 @@
       "resetToast": "Alterações restauradas."
     },
     "iconLabel": "Ícone",
-    "invalidDate": "Use uma data válida no formato selecionado."
+    "invalidDate": "Use uma data válida no formato selecionado.",
+    "attachmentLabel": "Anexo",
+    "attachmentHint": "Anexe uma imagem, PDF ou documento local. Imagens aparecem no pop-up do evento.",
+    "attachmentFallback": "Anexo",
+    "attachmentReadError": "Nao foi possivel ler o anexo.",
+    "attachmentTooLarge": "O anexo pode ter no maximo 5 MB."
   },
   "notes": {
     "title": "Quadro de notas",

public/locales/ru.json

@@ -358,7 +358,12 @@
       "resetToast": "Изменения сброшены."
     },
     "iconLabel": "Icon",
-    "invalidDate": "Use a valid date in the selected date format."
+    "invalidDate": "Use a valid date in the selected date format.",
+    "attachmentLabel": "Attachment",
+    "attachmentHint": "Attach a local image, PDF, or document. Images will be shown in the event popup.",
+    "attachmentFallback": "Attachment",
+    "attachmentReadError": "The attachment could not be read.",
+    "attachmentTooLarge": "Attachment may be at most 5 MB."
   },
   "notes": {
     "title": "Заметки",

public/locales/sv.json

@@ -358,7 +358,12 @@
       "resetToast": "Ändringar återställda."
     },
     "iconLabel": "Icon",
-    "invalidDate": "Use a valid date in the selected date format."
+    "invalidDate": "Use a valid date in the selected date format.",
+    "attachmentLabel": "Attachment",
+    "attachmentHint": "Attach a local image, PDF, or document. Images will be shown in the event popup.",
+    "attachmentFallback": "Attachment",
+    "attachmentReadError": "The attachment could not be read.",
+    "attachmentTooLarge": "Attachment may be at most 5 MB."
   },
   "notes": {
     "title": "Anteckningar",

public/locales/tr.json

@@ -358,7 +358,12 @@
       "resetToast": "Değişiklikler sıfırlandı."
     },
     "iconLabel": "Icon",
-    "invalidDate": "Use a valid date in the selected date format."
+    "invalidDate": "Use a valid date in the selected date format.",
+    "attachmentLabel": "Attachment",
+    "attachmentHint": "Attach a local image, PDF, or document. Images will be shown in the event popup.",
+    "attachmentFallback": "Attachment",
+    "attachmentReadError": "The attachment could not be read.",
+    "attachmentTooLarge": "Attachment may be at most 5 MB."
   },
   "notes": {
     "title": "Notlar",

public/locales/uk.json

@@ -358,7 +358,12 @@
       "resetToast": "Зміни скинуто."
     },
     "iconLabel": "Icon",
-    "invalidDate": "Use a valid date in the selected date format."
+    "invalidDate": "Use a valid date in the selected date format.",
+    "attachmentLabel": "Attachment",
+    "attachmentHint": "Attach a local image, PDF, or document. Images will be shown in the event popup.",
+    "attachmentFallback": "Attachment",
+    "attachmentReadError": "The attachment could not be read.",
+    "attachmentTooLarge": "Attachment may be at most 5 MB."
   },
   "notes": {
     "title": "Нотатки",

public/locales/zh.json

@@ -358,7 +358,12 @@
       "resetToast": "更改已重置。"
     },
     "iconLabel": "Icon",
-    "invalidDate": "Use a valid date in the selected date format."
+    "invalidDate": "Use a valid date in the selected date format.",
+    "attachmentLabel": "Attachment",
+    "attachmentHint": "Attach a local image, PDF, or document. Images will be shown in the event popup.",
+    "attachmentFallback": "Attachment",
+    "attachmentReadError": "The attachment could not be read.",
+    "attachmentTooLarge": "Attachment may be at most 5 MB."
   },
   "notes": {
     "title": "便签板",

public/pages/calendar.js

@@ -169,6 +169,8 @@ const EVENT_ICONS = [
 ];
 
 const CUSTOM_EVENT_ICONS = new Set(['tooth']);
+const MAX_ATTACHMENT_BYTES = 5 * 1024 * 1024;
+const ATTACHMENT_IMAGE_MIME = new Set(['image/png', 'image/jpeg', 'image/webp', 'image/gif']);
 
 const HOUR_HEIGHT = 56; // px pro Stunde in Wochen-/Tagesansicht
 
@@ -312,6 +314,35 @@ function eventIconElement(icon, className = 'event-icon') {
   return el;
 }
 
+function isImageAttachment(mime) {
+  return ATTACHMENT_IMAGE_MIME.has(String(mime || '').toLowerCase());
+}
+
+function readFileAsDataUrl(file) {
+  return new Promise((resolve, reject) => {
+    const reader = new FileReader();
+    reader.onload = () => resolve(String(reader.result || ''));
+    reader.onerror = () => reject(new Error(t('calendar.attachmentReadError')));
+    reader.readAsDataURL(file);
+  });
+}
+
+function attachmentHtml(event) {
+  if (!event?.attachment_data) return '';
+  const name = esc(event.attachment_name || t('calendar.attachmentFallback'));
+  if (isImageAttachment(event.attachment_mime)) {
+    return `
+      <div class="event-popup__attachment event-popup__attachment--image">
+        <img src="${event.attachment_data}" alt="${name}">
+      </div>`;
+  }
+  return `
+    <a class="event-popup__attachment event-popup__attachment--file" href="${event.attachment_data}" download="${name}">
+      <i data-lucide="paperclip" aria-hidden="true"></i>
+      <span>${name}</span>
+    </a>`;
+}
+
 function bindDateInputs(root) {
   root.querySelectorAll('.js-date-input').forEach((input) => {
     input.addEventListener('blur', () => {
@@ -631,6 +662,7 @@ function renderWeekView(container) {
   const timedEvs = days.map((d) =>
     eventsOnDay(d).filter((e) => !e.all_day && e.start_datetime.includes('T'))
   );
+  const layouts = timedEvs.map((events) => layoutOverlaps(events));
 
   container.innerHTML = `
     <div class="week-view">
@@ -674,7 +706,7 @@ function renderWeekView(container) {
                 ${Array.from({ length: 24 }, (_, h) => `
                   <div class="week-view__hour-line" style="top:${h * HOUR_HEIGHT}px;"></div>
                 `).join('')}
-                ${timedEvs[i].map((ev) => renderWeekEvent(ev)).join('')}
+                ${timedEvs[i].map((ev) => renderWeekEvent(ev, layouts[i].get(ev.id))).join('')}
                 ${d === state.today ? `<div class="week-view__now-line" id="now-line" style="top:${nowTop()}px;"></div>` : ''}
               </div>
             `).join('')}
@@ -712,19 +744,18 @@ function renderWeekView(container) {
   }
 }
 
-function renderWeekEvent(ev) {
+function renderWeekEvent(ev, layout = null) {
-  const start = timeToMinutes(localTime(ev.start_datetime));
+  const { start, end } = timeRangeForEvent(ev);
-  const end   = ev.end_datetime
-    ? timeToMinutes(localTime(ev.end_datetime))
-    : start + 60;
   const duration = Math.max(end - start, 30);
 
   const top    = (start / 60) * HOUR_HEIGHT;
   const height = (duration / 60) * HOUR_HEIGHT - 2;
+  const left = layout ? `calc(${(layout.colIndex / layout.totalCols) * 100}% + 2px)` : '2px';
+  const width = layout ? `calc(${100 / layout.totalCols}% - 4px)` : 'auto';
 
   return `
     <div class="week-event" data-id="${ev.id}"
-         style="top:${top}px;height:${height}px;${ev.cal_color || ev.color ? `background-color:${esc(ev.cal_color || ev.color)};` : ''}${getContrastColor(ev.cal_color || ev.color) ? `color:${getContrastColor(ev.cal_color || ev.color)};` : ''}">
+         style="top:${top}px;height:${height}px;left:${left};width:${width};${ev.cal_color || ev.color ? `background-color:${esc(ev.cal_color || ev.color)};` : ''}${getContrastColor(ev.cal_color || ev.color) ? `color:${getContrastColor(ev.cal_color || ev.color)};` : ''}">
       <div class="week-event__title">${eventIconHtml(ev.icon, 'event-icon event-icon--compact')}<span>${esc(ev.title)}</span></div>
       <div class="week-event__time">${formatTime(ev.start_datetime)}${ev.end_datetime ? '–' + formatTime(ev.end_datetime) : ''}</div>
     </div>
@@ -743,6 +774,66 @@ function nowTop() {
   return (minutes / 60) * HOUR_HEIGHT;
 }
 
+function timeRangeForEvent(ev) {
+  const start = timeToMinutes(localTime(ev.start_datetime));
+  const end = ev.end_datetime
+    ? timeToMinutes(localTime(ev.end_datetime))
+    : start + 60;
+  return {
+    start,
+    end: Math.max(end, start + 30),
+  };
+}
+
+function layoutOverlaps(events) {
+  const groups = [];
+  const sorted = [...events].sort((a, b) => {
+    const aRange = timeRangeForEvent(a);
+    const bRange = timeRangeForEvent(b);
+    return aRange.start - bRange.start || aRange.end - bRange.end;
+  });
+
+  let current = [];
+  let currentEnd = -1;
+  for (const ev of sorted) {
+    const range = timeRangeForEvent(ev);
+    if (!current.length || range.start < currentEnd) {
+      current.push(ev);
+      currentEnd = current.length === 1 ? range.end : Math.max(currentEnd, range.end);
+    } else {
+      groups.push(current);
+      current = [ev];
+      currentEnd = range.end;
+    }
+  }
+  if (current.length) groups.push(current);
+
+  const layout = new Map();
+  for (const group of groups) {
+    const columns = [];
+    const placements = [];
+    for (const ev of group) {
+      const range = timeRangeForEvent(ev);
+      let colIndex = columns.findIndex((end) => end <= range.start);
+      if (colIndex === -1) {
+        colIndex = columns.length;
+        columns.push(range.end);
+      } else {
+        columns[colIndex] = range.end;
+      }
+      placements.push({ ev, colIndex });
+    }
+    const totalCols = Math.max(columns.length, 1);
+    for (const placement of placements) {
+      layout.set(placement.ev.id, {
+        colIndex: placement.colIndex,
+        totalCols,
+      });
+    }
+  }
+  return layout;
+}
+
 // --------------------------------------------------------
 // Tagesansicht
 // --------------------------------------------------------
@@ -752,6 +843,7 @@ function renderDayView(container) {
   const dayEvs  = eventsOnDay(state.cursor);
   const allday  = dayEvs.filter((e) => e.all_day || !e.start_datetime.includes('T'));
   const timed   = dayEvs.filter((e) => !e.all_day && e.start_datetime.includes('T'));
+  const layout = layoutOverlaps(timed);
 
   container.innerHTML = `
     <div class="day-view">
@@ -781,7 +873,7 @@ function renderDayView(container) {
             ${Array.from({ length: 24 }, (_, h) => `
               <div class="week-view__hour-line" style="top:${h * HOUR_HEIGHT}px;"></div>
             `).join('')}
-            ${timed.map((ev) => renderWeekEvent(ev)).join('')}
+            ${timed.map((ev) => renderWeekEvent(ev, layout.get(ev.id))).join('')}
             ${state.cursor === state.today ? `<div class="week-view__now-line" style="top:${nowTop()}px;"></div>` : ''}
           </div>
         </div>
@@ -902,6 +994,7 @@ function showEventPopup(ev, anchor) {
       <div>${timeStr}</div>
       ${ev.location ? `<div>📍 ${esc(fmtLocation(ev.location))}</div>` : ''}
       ${ev.description ? `<div>${esc(ev.description)}</div>` : ''}
+      ${ev.attachment_data ? attachmentHtml(ev) : ''}
       ${ev.assigned_name ? `<div>👤 ${esc(ev.assigned_name)}</div>` : ''}
     </div>
     <div class="event-popup__actions">
@@ -1163,6 +1256,47 @@ function openEventModal({ mode, event = null, date = null, reminder = null }) {
 
       const reminderOffset = panel.querySelector('#modal-reminder-offset');
       const reminderCustom = panel.querySelector('#modal-reminder-custom');
+      const attachmentInput = panel.querySelector('#modal-attachment');
+      const attachmentPreview = panel.querySelector('#modal-attachment-preview');
+      const attachmentState = {
+        name: event?.attachment_name || null,
+        mime: event?.attachment_mime || null,
+        size: event?.attachment_size || null,
+        data: event?.attachment_data || null,
+      };
+      const syncAttachmentPreview = () => {
+        if (!attachmentPreview) return;
+        attachmentPreview.innerHTML = '';
+        if (!attachmentState.data) {
+          attachmentPreview.hidden = true;
+          return;
+        }
+        attachmentPreview.hidden = false;
+        if (isImageAttachment(attachmentState.mime)) {
+          attachmentPreview.innerHTML = `<img src="${attachmentState.data}" alt="${esc(attachmentState.name || '')}">`;
+        } else {
+          attachmentPreview.innerHTML = `<a href="${attachmentState.data}" download="${esc(attachmentState.name || '')}">${esc(attachmentState.name || '')}</a>`;
+        }
+      };
+      attachmentInput?.addEventListener('change', async () => {
+        const file = attachmentInput.files?.[0];
+        if (!file) return;
+        if (file.size > MAX_ATTACHMENT_BYTES) {
+          window.oikos?.showToast(t('calendar.attachmentTooLarge'), 'error');
+          attachmentInput.value = '';
+          return;
+        }
+        try {
+          attachmentState.data = await readFileAsDataUrl(file);
+          attachmentState.name = file.name;
+          attachmentState.mime = file.type || 'application/octet-stream';
+          attachmentState.size = file.size;
+          syncAttachmentPreview();
+        } catch (err) {
+          window.oikos?.showToast(err.message, 'danger');
+        }
+      });
+      syncAttachmentPreview();
       reminderOffset?.addEventListener('change', () => {
         if (reminderCustom) reminderCustom.hidden = reminderOffset.value !== 'custom';
       });
@@ -1174,7 +1308,7 @@ function openEventModal({ mode, event = null, date = null, reminder = null }) {
         await deleteEvent(event.id);
       });
 
-      panel.querySelector('#modal-save').addEventListener('click', () => saveEvent(panel, mode, event?.id, reminder));
+      panel.querySelector('#modal-save').addEventListener('click', () => saveEvent(panel, mode, event?.id, reminder, attachmentState));
       if (window.lucide) lucide.createIcons();
     },
   });
@@ -1309,6 +1443,19 @@ function buildEventModalContent({ mode, event, date, reminder = null }) {
                 placeholder="${t('calendar.descriptionPlaceholder')}">${esc(isEdit && event.description ? event.description : '')}</textarea>
     </div>
 
+    <div class="form-group">
+      <label class="form-label" for="modal-attachment">${t('calendar.attachmentLabel')}</label>
+      <input class="form-input" id="modal-attachment" type="file" accept="image/png,image/jpeg,image/webp,image/gif,application/pdf,text/plain,application/msword,application/vnd.openxmlformats-officedocument.wordprocessingml.document,application/vnd.ms-excel,application/vnd.openxmlformats-officedocument.spreadsheetml.sheet">
+      <div class="form-help">${t('calendar.attachmentHint')}</div>
+      <div class="event-attachment-preview" id="modal-attachment-preview" ${isEdit && event.attachment_data ? '' : 'hidden'}>
+        ${isEdit && event.attachment_data
+          ? (isImageAttachment(event.attachment_mime)
+            ? `<img src="${event.attachment_data}" alt="${esc(event.attachment_name || '')}">`
+            : `<a href="${event.attachment_data}" download="${esc(event.attachment_name || '')}">${esc(event.attachment_name || '')}</a>`)
+          : ''}
+      </div>
+    </div>
+
     ${renderRRuleFields('event', isEdit ? event.recurrence_rule : null)}
 
     ${renderCalendarReminderSection(reminder, event)}
@@ -1324,7 +1471,7 @@ function buildEventModalContent({ mode, event, date, reminder = null }) {
     </div>`;
 }
 
-async function saveEvent(overlay, mode, eventId, existingReminder = null) {
+async function saveEvent(overlay, mode, eventId, existingReminder = null, attachmentState = null) {
   const saveBtn = overlay.querySelector('#modal-save');
   const title   = overlay.querySelector('#modal-title').value.trim();
 
@@ -1382,6 +1529,10 @@ async function saveEvent(overlay, mode, eventId, existingReminder = null) {
       all_day: allday ? 1 : 0,
       location, color, icon, assigned_to: assigned_to ? parseInt(assigned_to, 10) : null,
       recurrence_rule: rrule.recurrence_rule,
+      attachment_name: attachmentState?.name || null,
+      attachment_mime: attachmentState?.mime || null,
+      attachment_size: attachmentState?.size || null,
+      attachment_data: attachmentState?.data || null,
     };
 
     let savedEventId = eventId;

public/styles/calendar.css

@@ -386,8 +386,6 @@
 
 .week-event {
   position: absolute;
-  left: 2px;
-  right: 2px;
   border-radius: var(--radius-xs);
   padding: var(--space-0h) var(--space-1);
   font-size: var(--text-xs);
@@ -419,6 +417,29 @@
   opacity: 0.85;
 }
 
+.event-attachment-preview {
+  display: flex;
+  flex-direction: column;
+  gap: var(--space-2);
+  margin-top: var(--space-2);
+}
+
+.event-attachment-preview img {
+  width: 100%;
+  max-height: 180px;
+  object-fit: cover;
+  border-radius: var(--radius-md);
+  border: 1px solid var(--color-border-subtle);
+}
+
+.event-attachment-preview a {
+  display: inline-flex;
+  align-items: center;
+  gap: var(--space-2);
+  color: var(--color-accent);
+  word-break: break-word;
+}
+
 /* --------------------------------------------------------
  * Tagesansicht
  * -------------------------------------------------------- */
@@ -763,6 +784,25 @@
   border-top: 1px solid var(--color-border);
 }
 
+.event-popup__attachment {
+  margin-top: var(--space-2);
+}
+
+.event-popup__attachment--image img {
+  width: 100%;
+  max-height: 220px;
+  object-fit: cover;
+  border-radius: var(--radius-md);
+  border: 1px solid var(--color-border-subtle);
+}
+
+.event-popup__attachment--file {
+  display: inline-flex;
+  align-items: center;
+  gap: var(--space-2);
+  color: var(--color-accent);
+}
+
 /* --------------------------------------------------------
  * Ganztägige Ereignisse (oben in Wochen-/Tagesansicht)
  * -------------------------------------------------------- */

server/db-schema-test.js

@@ -419,6 +419,12 @@ const MIGRATIONS_SQL = {
     CREATE INDEX IF NOT EXISTS idx_family_documents_created_by ON family_documents(created_by);
     CREATE INDEX IF NOT EXISTS idx_family_document_access_user ON family_document_access(user_id);
   `,
+  20: `
+    ALTER TABLE calendar_events ADD COLUMN attachment_name TEXT;
+    ALTER TABLE calendar_events ADD COLUMN attachment_mime TEXT;
+    ALTER TABLE calendar_events ADD COLUMN attachment_size INTEGER;
+    ALTER TABLE calendar_events ADD COLUMN attachment_data TEXT;
+  `,
 };
 
 export { MIGRATIONS_SQL };

server/db.js

@@ -853,6 +853,16 @@ const MIGRATIONS = [
       CREATE INDEX IF NOT EXISTS idx_family_document_access_user ON family_document_access(user_id);
     `,
   },
+  {
+    version: 27,
+    description: 'Calendar event attachments',
+    up: `
+      ALTER TABLE calendar_events ADD COLUMN attachment_name TEXT;
+      ALTER TABLE calendar_events ADD COLUMN attachment_mime TEXT;
+      ALTER TABLE calendar_events ADD COLUMN attachment_size INTEGER;
+      ALTER TABLE calendar_events ADD COLUMN attachment_data TEXT;
+    `,
+  },
 ];
 
 /**

server/openapi.js

@@ -349,7 +349,13 @@ function buildPaths() {
     },
     '/api/v1/calendar': {
       get: op({ summary: 'List calendar events', tag: 'Calendar' }),
-      post: op({ summary: 'Create calendar event', tag: 'Calendar', stateChanging: true, requestBody: jsonBody(null) }),
+      post: op({
+        summary: 'Create calendar event',
+        tag: 'Calendar',
+        stateChanging: true,
+        description: 'Supports optional local file attachments via `attachment_name`, `attachment_mime`, `attachment_size`, and `attachment_data` (base64 data URL).',
+        requestBody: jsonBody(null),
+      }),
     },
     '/api/v1/calendar/upcoming': { get: op({ summary: 'List upcoming events', tag: 'Calendar' }) },
     '/api/v1/calendar/google/auth': { get: op({ summary: 'Start Google Calendar OAuth', tag: 'Calendar', admin: true }) },
@@ -374,7 +380,14 @@ function buildPaths() {
     },
     '/api/v1/calendar/{id}': {
       get: op({ summary: 'Get calendar event', tag: 'Calendar', params: [idParam()] }),
-      put: op({ summary: 'Update calendar event', tag: 'Calendar', params: [idParam()], stateChanging: true, requestBody: jsonBody(null) }),
+      put: op({
+        summary: 'Update calendar event',
+        tag: 'Calendar',
+        params: [idParam()],
+        stateChanging: true,
+        description: 'Supports optional local file attachments via `attachment_name`, `attachment_mime`, `attachment_size`, and `attachment_data` (base64 data URL).',
+        requestBody: jsonBody(null),
+      }),
       delete: op({ summary: 'Delete calendar event', tag: 'Calendar', params: [idParam()], stateChanging: true }),
     },
     '/api/v1/calendar/{id}/reset': {

server/routes/calendar.js

@@ -20,6 +20,19 @@ const log = createLogger('Calendar');
 const router         = express.Router();
 
 const VALID_SOURCES  = ['local', 'google', 'apple', 'ics'];
+const MAX_ATTACHMENT_BYTES = 5 * 1024 * 1024;
+const ATTACHMENT_MIME = new Set([
+  'image/png',
+  'image/jpeg',
+  'image/webp',
+  'image/gif',
+  'application/pdf',
+  'text/plain',
+  'application/msword',
+  'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
+  'application/vnd.ms-excel',
+  'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
+]);
 const ICS_COLOR_RE   = /^#[0-9a-fA-F]{6}$/;
 const VALID_EVENT_ICONS = new Set([
   'calendar', 'tooth', 'drill', 'alarm-clock', 'clock', 'bell', 'map-pin', 'home',
@@ -59,6 +72,20 @@ function eventIcon(value) {
   return VALID_EVENT_ICONS.has(icon) ? icon : null;
 }
 
+function parseAttachment(dataUrl) {
+  const raw = typeof dataUrl === 'string' ? dataUrl.trim() : '';
+  if (!raw) return { name: null, mime: null, size: null, data: null };
+  const match = raw.match(/^data:([^;,]+);base64,([A-Za-z0-9+/=\s]+)$/);
+  if (!match) throw new Error('attachment_data: ungültiges Dateiformat.');
+  const mime = match[1].toLowerCase();
+  if (!ATTACHMENT_MIME.has(mime)) throw new Error('attachment_data: Dateityp nicht erlaubt.');
+  const base64 = match[2].replace(/\s/g, '');
+  const buffer = Buffer.from(base64, 'base64');
+  if (!buffer.length) throw new Error('attachment_data: Datei ist leer.');
+  if (buffer.length > MAX_ATTACHMENT_BYTES) throw new Error('attachment_data: Datei darf höchstens 5 MB groß sein.');
+  return { name: null, mime, size: buffer.length, data: base64 };
+}
+
 // --------------------------------------------------------
 // RRULE-Expansion: alle Vorkommen eines wiederkehrenden Events
 // innerhalb [from, to] generieren (inklusive beider Grenzen).
@@ -591,17 +618,24 @@ router.post('/', (req, res) => {
       if (!user) return res.status(400).json({ error: 'assigned_to: Benutzer nicht gefunden', code: 400 });
     }
 
+    const attachment = req.body.attachment_data ? parseAttachment(req.body.attachment_data) : { mime: null, size: null, data: null };
+
     const result = db.get().prepare(`
       INSERT INTO calendar_events
         (title, description, start_datetime, end_datetime, all_day,
-         location, color, icon, assigned_to, created_by, recurrence_rule)
+         location, color, icon, assigned_to, created_by, recurrence_rule,
-      VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+         attachment_name, attachment_mime, attachment_size, attachment_data)
+      VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
     `).run(
       vTitle.value, vDesc.value,
       vStart.value, vEnd.value,
       all_day ? 1 : 0, vLoc.value,
       vColor.value, vIcon, assigned_to || null,
-      userId, vRrule.value
+      userId, vRrule.value,
+      req.body.attachment_name || null,
+      attachment.mime,
+      attachment.size,
+      attachment.data
     );
 
     const event = db.get().prepare(`
@@ -646,10 +680,17 @@ router.put('/:id', (req, res) => {
     if (errors.length) return res.status(400).json({ error: errors.join(' '), code: 400 });
     const vIcon = req.body.icon !== undefined ? eventIcon(req.body.icon) : event.icon;
     if (!vIcon) return res.status(400).json({ error: 'icon: invalid calendar event icon.', code: 400 });
+    const attachment = req.body.attachment_data !== undefined
+      ? (req.body.attachment_data ? parseAttachment(req.body.attachment_data) : { mime: null, size: null, data: null })
+      : {
+          mime: event.attachment_mime,
+          size: event.attachment_size,
+          data: event.attachment_data,
+        };
 
     const {
       title, description, start_datetime, end_datetime,
-      all_day, location, color: colorVal, assigned_to, recurrence_rule,
+      all_day, location, color: colorVal, assigned_to, recurrence_rule, attachment_name,
     } = req.body;
 
     const userModified = event.external_source !== 'local' ? 1 : event.user_modified;
@@ -666,6 +707,10 @@ router.put('/:id', (req, res) => {
           icon            = COALESCE(?, icon),
           assigned_to     = ?,
           recurrence_rule = ?,
+          attachment_name = ?,
+          attachment_mime  = ?,
+          attachment_size  = ?,
+          attachment_data  = ?,
           user_modified   = ?
       WHERE id = ?
     `).run(
@@ -679,6 +724,10 @@ router.put('/:id', (req, res) => {
       req.body.icon !== undefined ? vIcon : null,
       assigned_to !== undefined ? (assigned_to || null) : event.assigned_to,
       recurrence_rule !== undefined ? (recurrence_rule || null) : event.recurrence_rule,
+      attachment_name !== undefined ? (attachment_name || null) : event.attachment_name,
+      attachment.mime,
+      attachment.size,
+      attachment.data,
       userModified,
       id
     );