feat: obsolete medication archiving, start date, and UI improvements (#215)

* feat: obsolete medication archiving, start date, and UI improvements

- Add soft-archive (obsolete) for medications with dedicated section and toggle
- Add medication start date field with date picker and validation
- Add obsolete/reactivate API endpoints with proper auth
- Filter obsolete meds from schedule, coverage, planner, and notifications
- Improve UserFilterModal with intake schedules, stock badges, and click-to-open
- Improve dashboard taken-by badges with per-intake bell icons
- Add Escape key support to ConfirmModal and MobileEditModal
- Fix Lightbox close button positioning near image
- Add read-only mode support for MobileEditModal
- DB migrations: 0008 (is_obsolete, obsolete_at), 0009 (medication_start_date)
- All user-facing text uses i18n keys (en + de)

* test: fix tests for obsolete medications and UI changes

- Backend: add is_obsolete, obsolete_at, medication_start_date columns to test schemas
- Backend: add test medication inserts in planner tests for active-med filtering
- Frontend: update useMedications URL to include includeObsolete param
- Frontend: fix MobileEditModal selectors and validation assertions
- Frontend: add onClearUser prop to UserFilterModal test renders
- Frontend: fix MedicationsPage and DashboardPage test assertions

frontend/src/pages/PlannerPage.tsx

@@ -1,6 +1,6 @@
 import { useEffect, useState } from "react";
 import { useTranslation } from "react-i18next";
-import { MedicationAvatar } from "../components";
+import { DateTimeInput, MedicationAvatar } from "../components";
 import { useAuth } from "../components/Auth";
 import { useAppContext } from "../context";
 import type { PlannerRow } from "../types";
@@ -158,8 +158,7 @@ export function PlannerPage() {
 				<form className="planner" onSubmit={runPlanner}>
 					<label>
 						{t("planner.from")}
-						<input
-							type="datetime-local"
+						<DateTimeInput
 							step="60"
 							value={range.start}
 							onChange={(e) => setRange({ ...range, start: e.target.value })}
@@ -167,12 +166,7 @@ export function PlannerPage() {
 					</label>
 					<label>
 						{t("planner.until")}
-						<input
-							type="datetime-local"
-							step="60"
-							value={range.end}
-							onChange={(e) => setRange({ ...range, end: e.target.value })}
-						/>
+						<DateTimeInput step="60" value={range.end} onChange={(e) => setRange({ ...range, end: e.target.value })} />
 					</label>
 					<label className="planner-checkbox">
 						<input