feat(tasks): add optional "none" priority level for tasks without urgency

New tasks default to "none" priority instead of "medium". Tasks with no
priority hide the badge in list and dashboard views, reducing visual noise
for routine items. Includes DB migration v4 and i18n keys (de, en, it).

Closes #15

public/locales/de.json

@@ -100,6 +100,7 @@
     "priorityHigh": "Hoch",
     "priorityMedium": "Mittel",
     "priorityLow": "Niedrig",
+    "priorityNone": "Keine",
     "statusOpen": "Offen",
     "statusInProgress": "In Bearbeitung",
     "statusDone": "Erledigt",

public/locales/en.json

@@ -100,6 +100,7 @@
     "priorityHigh": "High",
     "priorityMedium": "Medium",
     "priorityLow": "Low",
+    "priorityNone": "None",
     "statusOpen": "Open",
     "statusInProgress": "In Progress",
     "statusDone": "Done",

public/locales/it.json

@@ -100,6 +100,7 @@
     "priorityHigh": "Alta",
     "priorityMedium": "Media",
     "priorityLow": "Bassa",
+    "priorityNone": "Nessuna",
     "statusOpen": "Aperto",
     "statusInProgress": "In corso",
     "statusDone": "Completato",

public/pages/dashboard.js

@@ -167,7 +167,7 @@ function renderUrgentTasks(tasks) {
     const due = formatDueDate(t.due_date);
     return `
       <div class="task-item" data-route="/tasks" role="button" tabindex="0">
-        <div class="task-item__priority task-item__priority--${t.priority}" aria-hidden="true"></div>
+        ${t.priority !== 'none' ? `<div class="task-item__priority task-item__priority--${t.priority}" aria-hidden="true"></div>` : ''}
         <span class="sr-only">${PRIORITY_LABELS()[t.priority] ?? t.priority}</span>
         <div class="task-item__content">
           <div class="task-item__title">${esc(t.title)}</div>

public/pages/tasks.js

@@ -20,6 +20,7 @@ const PRIORITIES = () => [
   { value: 'high',   label: t('tasks.priorityHigh'),   color: 'var(--color-priority-high)'   },
   { value: 'medium', label: t('tasks.priorityMedium'), color: 'var(--color-priority-medium)' },
   { value: 'low',    label: t('tasks.priorityLow'),    color: 'var(--color-priority-low)'    },
+  { value: 'none',   label: t('tasks.priorityNone'),   color: 'var(--color-priority-none)'   },
 ];
 
 const STATUSES = () => [
@@ -110,6 +111,7 @@ function groupBy(tasks, mode) {
 // --------------------------------------------------------
 
 function renderPriorityBadge(priority) {
+  if (priority === 'none') return '';
   return `<span class="priority-badge priority-badge--${priority}">
     <span class="priority-dot priority-dot--${priority}"></span>
     ${PRIORITY_LABELS()[priority] ?? priority}
@@ -254,7 +256,7 @@ function renderModalContent({ task = null, users = [] } = {}) {
   ).join('');
 
   const priorityOptions = PRIORITIES().map((p) =>
-    `<option value="${p.value}" ${(task?.priority ?? 'medium') === p.value ? 'selected' : ''}>${p.label}</option>`
+    `<option value="${p.value}" ${(task?.priority ?? 'none') === p.value ? 'selected' : ''}>${p.label}</option>`
   ).join('');
 
   return `

public/styles/tokens.css

@@ -114,12 +114,14 @@
   /* --------------------------------------------------------
    * 6. Farben - Prioritäten
    * -------------------------------------------------------- */
+  --color-priority-none:   var(--neutral-400);
   --color-priority-low:    var(--neutral-500);
   --color-priority-medium: #B45309;
   --color-priority-high:   #D4511E;
   --color-priority-urgent: #DC2626;
 
   /* Hintergrundfarben für Priority-Badges */
+  --color-priority-none-bg:   rgba(142, 141, 137, 0.08);
   --color-priority-low-bg:    rgba(142, 141, 137, 0.12);
   --color-priority-medium-bg: rgba(180, 83, 9, 0.12);
   --color-priority-high-bg:   rgba(212, 81, 30, 0.12);
@@ -328,6 +330,7 @@
     --meal-snack-light:     #3D2010;
 
     /* Priority-Badge Hintergründe */
+    --color-priority-none-bg:   rgba(142, 141, 137, 0.12);
     --color-priority-low-bg:    rgba(142, 141, 137, 0.18);
     --color-priority-medium-bg: rgba(230, 147, 10, 0.18);
     --color-priority-high-bg:   rgba(212, 81, 30, 0.18);
@@ -408,6 +411,7 @@
   --meal-dinner-light:    #1A2D4D;
   --meal-snack-light:     #3D2010;
 
+  --color-priority-none-bg:   rgba(142, 141, 137, 0.12);
   --color-priority-low-bg:    rgba(142, 141, 137, 0.18);
   --color-priority-medium-bg: rgba(230, 147, 10, 0.18);
   --color-priority-high-bg:   rgba(212, 81, 30, 0.18);

public/sw.js

@@ -12,9 +12,9 @@
  *   API: Immer Netzwerk (kein Caching von Nutzerdaten)
  */
 
-const SHELL_CACHE   = 'oikos-shell-v23';
-const PAGES_CACHE   = 'oikos-pages-v23';
-const ASSETS_CACHE  = 'oikos-assets-v23';
+const SHELL_CACHE   = 'oikos-shell-v24';
+const PAGES_CACHE   = 'oikos-pages-v24';
+const ASSETS_CACHE  = 'oikos-assets-v24';
 const ALL_CACHES    = [SHELL_CACHE, PAGES_CACHE, ASSETS_CACHE];
 
 // App-Shell: sofort benötigt für ersten Render