feat: theme dropdown with system preference and comprehensive bottle-type fixes (#138)

- Replace dark/light toggle with Light/Dark/System dropdown menu
- System theme follows OS prefers-color-scheme setting
- Apply theme dropdown to shared schedule page
- Fix 7 packageType (bottle) bugs across stock calc, share, refills, export/import
- Fix planner bottle-type stock calculation and display
- Fix dailyRate double-counting with per-intake takenBy
- Fix About modal update check stale caching
- Fix intake reminder past-intake seeding and push title
- Fix phantom DB path in drizzle.config.ts
- Fix mobile dose field visibility
- Make medication name clickable in dashboard reminder bar
- Improve planner checkbox UX with inline tooltip
- Add 20+ new tests covering all fixes

frontend/src/i18n/de.json

@@ -176,7 +176,8 @@
     "badge": "Vorrat planen",
     "from": "Von",
     "until": "Bis",
-    "includeUntilStart": "Verbrauch von heute bis Startdatum einrechnen",
+    "includeUntilStart": "Aktuellen Verbrauch einrechnen",
+    "includeUntilStartTooltip": "Wenn aktiviert, werden die Pillen, die zwischen heute und dem gewählten Startdatum verbraucht werden, vom aktuellen Bestand abgezogen. So erhältst du ein genaueres Bild davon, wie viel du zu Beginn des Planungszeitraums tatsächlich noch übrig hast.",
     "calculate": "Berechnen",
     "calculating": "Wird berechnet...",
     "sendEmail": "📧 Per E-Mail senden",
@@ -290,6 +291,12 @@
     "lightMode": "Zum hellen Modus wechseln",
     "darkMode": "Zum dunklen Modus wechseln"
   },
+  "theme": {
+    "title": "Design",
+    "light": "Hell",
+    "dark": "Dunkel",
+    "system": "System"
+  },
   "dose": {
     "takenBy": "eingenommen von",
     "markAsTaken": "Als eingenommen markieren"
@@ -478,10 +485,9 @@
     "checking": "Prüfe...",
     "upToDate": "Du bist auf dem neuesten Stand!",
     "updateAvailable": "Update verfügbar",
-    "viewOnGitHub": "Auf GitHub ansehen",
     "downloadUpdate": "Update herunterladen",
     "checkFailed": "Update-Prüfung fehlgeschlagen",
-    "lastChecked": "Zuletzt geprüft",
+    "viewOnGitHub": "Auf GitHub ansehen",
     "github": "GitHub",
     "license": "MIT-Lizenz",
     "copyright": "© {{year}} Daniel Volz",

frontend/src/i18n/en.json

@@ -176,7 +176,8 @@
     "badge": "Plan your supply",
     "from": "From",
     "until": "Until",
-    "includeUntilStart": "Include consumption from today until start date",
+    "includeUntilStart": "Include current consumption",
+    "includeUntilStartTooltip": "When enabled, pills consumed between today and the selected start date are subtracted from your current stock. This gives a more accurate picture of how much you'll actually have left when the planning period begins.",
     "calculate": "Calculate",
     "calculating": "Calculating...",
     "sendEmail": "📧 Send via Email",
@@ -290,6 +291,12 @@
     "lightMode": "Switch to light mode",
     "darkMode": "Switch to dark mode"
   },
+  "theme": {
+    "title": "Theme",
+    "light": "Light",
+    "dark": "Dark",
+    "system": "System"
+  },
   "dose": {
     "takenBy": "taken by",
     "markAsTaken": "Mark as taken"
@@ -478,10 +485,9 @@
     "checking": "Checking...",
     "upToDate": "You're up to date!",
     "updateAvailable": "Update available",
-    "viewOnGitHub": "View on GitHub",
     "downloadUpdate": "Download Update",
     "checkFailed": "Could not check for updates",
-    "lastChecked": "Last checked",
+    "viewOnGitHub": "View on GitHub",
     "github": "GitHub",
     "license": "MIT License",
     "copyright": "© {{year}} Daniel Volz",