Add missing translations for task management features

Integrates i18next for internationalization, adding translated strings for task details, search, filters, and calendar views in both English and German.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: ceced2fc-aa46-458d-ba87-ddd4b7bb1518
Replit-Commit-Checkpoint-Type: intermediate_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/659922a9-0087-461c-90dd-6d9a58b81d4d/ceced2fc-aa46-458d-ba87-ddd4b7bb1518/E3NLe8e

client/src/i18n/locales/en.json

@@ -17,6 +17,9 @@
     "searchPlaceholder": "Search tasks...",
     "noTasks": "No tasks yet. Create your first task!",
     "noMatchingTasks": "No tasks match your filters",
+    "noUnscheduledTasks": "No unscheduled tasks. Drag tasks to the calendar below to schedule them!",
+    "unscheduledTasksLabel": "Unscheduled Tasks - Drag to calendar below to schedule",
+    "calendarTitle": "Next {{count}} Days",
     "filter": {
       "all": "All",
       "todo": "To Do",
@@ -74,6 +77,7 @@
     "status": "Status",
     "label": "Label",
     "noLabel": "No Label",
+    "selectLabel": "Select a label",
     "dueDate": "Due Date",
     "selectDate": "Select date",
     "notes": "Notes",
@@ -81,7 +85,33 @@
     "timeTracked": "Time Tracked",
     "delete": "Delete Task",
     "cancel": "Cancel",
-    "save": "Save Changes"
+    "save": "Save Changes",
+    "tracked": "tracked",
+    "priorityValue": {
+      "low": "Low Priority",
+      "medium": "Medium Priority",
+      "high": "High Priority"
+    },
+    "statusValue": {
+      "todo": "To Do",
+      "inProgress": "In Progress",
+      "done": "Done"
+    },
+    "editTab": "Edit",
+    "notesTab": "Notes",
+    "timeTab": "Time Tracking",
+    "editTask": "Edit Task",
+    "titleLabel": "Title",
+    "titlePlaceholder": "Task title",
+    "taskNotes": "Task Notes",
+    "edit": "Edit",
+    "noNotesYet": "No notes added yet. Click \"Edit\" to add notes.",
+    "totalTimeTracked": "Total Time Tracked",
+    "addTime": "Add Time",
+    "addTimeEntry": "Add Time Entry",
+    "clock": "Clock",
+    "manual": "Manual",
+    "previouslyTrackedTime": "Previously tracked time"
   },
   "taskCard": {
     "play": "Start timer",