feat: Implement internationalization for task management components

- Added translation support for task-related strings in ProjectTaskForm and ProjectTasksSection components.
- Integrated translation for navigation items in the Navigation component.
- Created ProjectCalendarWidget component with Polish translations for project statuses and deadlines.
- Developed Tooltip component for enhanced user experience with tooltips.
- Established a field change history logging system in the database with associated queries.
- Enhanced task update logging to include translated status and priority changes.
- Introduced server-side translations for system messages to improve localization.

src/lib/i18n.js

@@ -12,6 +12,7 @@ const translations = {
     navigation: {
       dashboard: "Panel główny",
       projects: "Projekty", 
+      calendar: "Kalendarz",
       taskTemplates: "Szablony zadań",
       projectTasks: "Zadania projektów",
       contracts: "Umowy",
@@ -62,7 +63,14 @@ const translations = {
       addNote: "Dodaj notatkę",
       addNoteSuccess: "Notatka została dodana",
       addNoteError: "Nie udało się zapisać notatki",
-      addNotePlaceholder: "Dodaj nową notatkę..."
+      addNotePlaceholder: "Dodaj nową notatkę...",
+      status: "Status",
+      type: "Typ",
+      actions: "Akcje",
+      view: "Wyświetl",
+      clearSearch: "Wyczyść wyszukiwanie",
+      clearAllFilters: "Wyczyść wszystkie filtry",
+      sortBy: "Sortuj według"
     },
 
     // Dashboard
@@ -127,9 +135,10 @@ const translations = {
       city: "Miasto",
       address: "Adres",
       plot: "Działka",
-      district: "Dzielnica",
-      unit: "Jednostka",
+      district: "Jednostka ewidencyjna",
+      unit: "Obręb",
       finishDate: "Data zakończenia",
+      type: "Typ",
       contact: "Kontakt",
       coordinates: "Współrzędne",
       notes: "Notatki",
@@ -144,19 +153,44 @@ const translations = {
       searchPlaceholder: "Szukaj projektów po nazwie, mieście lub adresie...",
       noProjects: "Brak projektów",
       noProjectsMessage: "Rozpocznij od utworzenia swojego pierwszego projektu.",
+      notFinished: "Nie zakończone",
+      projects: "projektów",
+      mapView: "Widok mapy",
+      createFirstProject: "Utwórz pierwszy projekt",
+      noMatchingResults: "Brak projektów pasujących do kryteriów wyszukiwania. Spróbuj zmienić wyszukiwane frazy.",
+      showingResults: "Wyświetlono {shown} z {total} projektów",
       deleteConfirm: "Czy na pewno chcesz usunąć ten projekt?",
       deleteSuccess: "Projekt został pomyślnie usunięty",
       createSuccess: "Projekt został pomyślnie utworzony", 
       updateSuccess: "Projekt został pomyślnie zaktualizowany",
+      saveError: "Nie udało się zapisać projektu",
       enterProjectName: "Wprowadź nazwę projektu",
       enterCity: "Wprowadź miasto",
       enterAddress: "Wprowadź adres",
       enterPlotNumber: "Wprowadź numer działki",
-      enterDistrict: "Wprowadź dzielnicę",
-      enterUnit: "Wprowadź jednostkę",
+      enterDistrict: "Wprowadź jednostkę ewidencyjną",
+      enterUnit: "Wprowadź obręb",
       enterContactDetails: "Wprowadź dane kontaktowe",
       coordinatesPlaceholder: "np. 49.622958,20.629562",
-      enterNotes: "Wprowadź notatki..."
+      enterNotes: "Wprowadź notatki...",
+      createProject: "Utwórz projekt",
+      updateProject: "Aktualizuj projekt",
+      creating: "Tworzenie...",
+      updating: "Aktualizowanie...",
+      projectDetails: "Szczegóły projektu",
+      editProjectDetails: "Edytuj szczegóły projektu",
+      contract: "Umowa",
+      selectContract: "Wybierz umowę",
+      investmentNumber: "Numer inwestycji",
+      enterInvestmentNumber: "Wprowadź numer inwestycji",
+      enterWP: "Wprowadź WP",
+      placeholders: {
+        contact: "Wprowadź dane kontaktowe",
+        coordinates: "np. 49.622958,20.629562",
+        notes: "Wprowadź notatki...",
+        investmentNumber: "Wprowadź numer inwestycji",
+        wp: "Wprowadź WP"
+      }
     },
 
     // Contracts
@@ -240,6 +274,19 @@ const translations = {
       actions: "Działania",
       urgent: "Pilne",
       updateTask: "Aktualizuj zadanie",
+      taskType: "Typ zadania",
+      fromTemplate: "Z szablonu",
+      customTask: "Zadanie niestandardowe",
+      selectTemplate: "Wybierz szablon zadania",
+      chooseTemplate: "Wybierz szablon zadania...",
+      enterTaskName: "Wprowadź nazwę zadania...",
+      enterDescription: "Wprowadź opis zadania (opcjonalnie)...",
+      addTask: "Dodaj zadanie",
+      adding: "Dodawanie...",
+      addTaskError: "Nie udało się dodać zadania do projektu",
+      notes: "notatki", 
+      deleteNote: "Usuń notatkę",
+      deleteError: "Błąd usuwania zadania",
       notStarted: "Nie rozpoczęte",
       days: "dni"
     },
@@ -454,7 +501,14 @@ const translations = {
       addNote: "Add Note",
       addNoteSuccess: "Note added",
       addNoteError: "Failed to save note",
-      addNotePlaceholder: "Add a new note..."
+      addNotePlaceholder: "Add a new note...",
+      status: "Status",
+      type: "Type", 
+      actions: "Actions",
+      view: "View",
+      clearSearch: "Clear search",
+      clearAllFilters: "Clear all filters",
+      sortBy: "Sort by"
     },
 
     dashboard: {
@@ -517,6 +571,7 @@ const translations = {
       district: "District",
       unit: "Unit",
       finishDate: "Finish Date",
+      type: "Type",
       contact: "Contact",
       coordinates: "Coordinates",
       notes: "Notes",
@@ -531,10 +586,17 @@ const translations = {
       searchPlaceholder: "Search projects by name, city or address...",
       noProjects: "No projects",
       noProjectsMessage: "Get started by creating your first project.",
+      notFinished: "Not finished",
+      projects: "projects", 
+      mapView: "Map View",
+      createFirstProject: "Create first project",
+      noMatchingResults: "No projects match the search criteria. Try changing your search terms.",
+      showingResults: "Showing {shown} of {total} projects",
       deleteConfirm: "Are you sure you want to delete this project?",
       deleteSuccess: "Project deleted successfully",
       createSuccess: "Project created successfully",
       updateSuccess: "Project updated successfully",
+      saveError: "Failed to save project",
       enterProjectName: "Enter project name",
       enterCity: "Enter city",
       enterAddress: "Enter address",
@@ -543,7 +605,25 @@ const translations = {
       enterUnit: "Enter unit",
       enterContactDetails: "Enter contact details",
       coordinatesPlaceholder: "e.g., 49.622958,20.629562",
-      enterNotes: "Enter notes..."
+      enterNotes: "Enter notes...",
+      createProject: "Create Project",
+      updateProject: "Update Project", 
+      creating: "Creating...",
+      updating: "Updating...",
+      projectDetails: "Project Details",
+      editProjectDetails: "Edit Project Details",
+      contract: "Contract",
+      selectContract: "Select Contract",
+      investmentNumber: "Investment Number",
+      enterInvestmentNumber: "Enter investment number",
+      enterWP: "Enter WP",
+      placeholders: {
+        contact: "Enter contact details",
+        coordinates: "e.g., 49.622958,20.629562",
+        notes: "Enter notes...",
+        investmentNumber: "Enter investment number",
+        wp: "Enter WP"
+      }
     },
 
     contracts: {
@@ -625,6 +705,19 @@ const translations = {
       actions: "Actions",
       urgent: "Urgent",
       updateTask: "Update Task",
+      taskType: "Task Type",
+      fromTemplate: "From Template",
+      customTask: "Custom Task",
+      selectTemplate: "Select Task Template",
+      chooseTemplate: "Choose a task template...",
+      enterTaskName: "Enter custom task name...",
+      enterDescription: "Enter task description (optional)...",
+      addTask: "Add Task",
+      adding: "Adding...",
+      addTaskError: "Failed to add task to project",
+      notes: "notes",
+      deleteNote: "Delete note", 
+      deleteError: "Error deleting task",
       notStarted: "Not started",
       days: "days"
     },

src/lib/init-db.js

@@ -362,5 +362,24 @@ export default function initializeDatabase() {
 		-- Create indexes for file attachments
 		CREATE INDEX IF NOT EXISTS idx_file_attachments_entity ON file_attachments(entity_type, entity_id);
 		CREATE INDEX IF NOT EXISTS idx_file_attachments_uploaded_by ON file_attachments(uploaded_by);
+
+		-- Generic field change history table
+		CREATE TABLE IF NOT EXISTS field_change_history (
+			id INTEGER PRIMARY KEY AUTOINCREMENT,
+			table_name TEXT NOT NULL,
+			record_id INTEGER NOT NULL,
+			field_name TEXT NOT NULL,
+			old_value TEXT,
+			new_value TEXT,
+			changed_by INTEGER,
+			changed_at TEXT DEFAULT CURRENT_TIMESTAMP,
+			change_reason TEXT,
+			FOREIGN KEY (changed_by) REFERENCES users(id)
+		);
+
+		-- Create indexes for field change history
+		CREATE INDEX IF NOT EXISTS idx_field_history_table_record ON field_change_history(table_name, record_id);
+		CREATE INDEX IF NOT EXISTS idx_field_history_field ON field_change_history(table_name, record_id, field_name);
+		CREATE INDEX IF NOT EXISTS idx_field_history_changed_by ON field_change_history(changed_by);
 	`);
 }

src/lib/queries/fieldHistory.js

@@ -0,0 +1,94 @@
+import db from "../db.js";
+
+/**
+ * Log a field change to the history table
+ */
+export function logFieldChange(tableName, recordId, fieldName, oldValue, newValue, changedBy = null, reason = null) {
+	// Don't log if values are the same
+	if (oldValue === newValue) return null;
+
+	const stmt = db.prepare(`
+		INSERT INTO field_change_history 
+		(table_name, record_id, field_name, old_value, new_value, changed_by, change_reason)
+		VALUES (?, ?, ?, ?, ?, ?, ?)
+	`);
+
+	return stmt.run(
+		tableName,
+		recordId,
+		fieldName,
+		oldValue || null,
+		newValue || null,
+		changedBy,
+		reason
+	);
+}
+
+/**
+ * Get field change history for a specific field
+ */
+export function getFieldHistory(tableName, recordId, fieldName) {
+	const stmt = db.prepare(`
+		SELECT 
+			fch.*,
+			u.name as changed_by_name,
+			u.username as changed_by_username
+		FROM field_change_history fch
+		LEFT JOIN users u ON fch.changed_by = u.id
+		WHERE fch.table_name = ? AND fch.record_id = ? AND fch.field_name = ?
+		ORDER BY fch.changed_at DESC
+	`);
+
+	return stmt.all(tableName, recordId, fieldName);
+}
+
+/**
+ * Get all field changes for a specific record
+ */
+export function getAllFieldHistory(tableName, recordId) {
+	const stmt = db.prepare(`
+		SELECT 
+			fch.*,
+			u.name as changed_by_name,
+			u.username as changed_by_username
+		FROM field_change_history fch
+		LEFT JOIN users u ON fch.changed_by = u.id
+		WHERE fch.table_name = ? AND fch.record_id = ?
+		ORDER BY fch.changed_at DESC, fch.field_name ASC
+	`);
+
+	return stmt.all(tableName, recordId);
+}
+
+/**
+ * Check if a field has any change history
+ */
+export function hasFieldHistory(tableName, recordId, fieldName) {
+	const stmt = db.prepare(`
+		SELECT COUNT(*) as count
+		FROM field_change_history 
+		WHERE table_name = ? AND record_id = ? AND field_name = ?
+	`);
+
+	const result = stmt.get(tableName, recordId, fieldName);
+	return result.count > 0;
+}
+
+/**
+ * Get the most recent change for a field
+ */
+export function getLatestFieldChange(tableName, recordId, fieldName) {
+	const stmt = db.prepare(`
+		SELECT 
+			fch.*,
+			u.name as changed_by_name,
+			u.username as changed_by_username
+		FROM field_change_history fch
+		LEFT JOIN users u ON fch.changed_by = u.id
+		WHERE fch.table_name = ? AND fch.record_id = ? AND fch.field_name = ?
+		ORDER BY fch.changed_at DESC
+		LIMIT 1
+	`);
+
+	return stmt.get(tableName, recordId, fieldName);
+}

src/lib/queries/notes.js

@@ -6,7 +6,7 @@ export function getNotesByProjectId(project_id) {
 			`
 			SELECT n.*, 
 			       u.name as created_by_name,
-			       u.email as created_by_email
+			       u.username as created_by_username
 			FROM notes n
 			LEFT JOIN users u ON n.created_by = u.id
 			WHERE n.project_id = ? 
@@ -31,7 +31,7 @@ export function getNotesByTaskId(task_id) {
 			`
 			SELECT n.*, 
 			       u.name as created_by_name,
-			       u.email as created_by_email
+			       u.username as created_by_username
 			FROM notes n
 			LEFT JOIN users u ON n.created_by = u.id
 			WHERE n.task_id = ? 
@@ -64,7 +64,7 @@ export function getAllNotesWithUsers() {
 			`
 			SELECT n.*,
 			       u.name as created_by_name,
-			       u.email as created_by_email,
+			       u.username as created_by_username,
 			       p.project_name,
 			       COALESCE(pt.custom_task_name, t.name) as task_name
 			FROM notes n
@@ -85,7 +85,7 @@ export function getNotesByCreator(userId) {
 			`
 			SELECT n.*,
 			       u.name as created_by_name,
-			       u.email as created_by_email,
+			       u.username as created_by_username,
 			       p.project_name,
 			       COALESCE(pt.custom_task_name, t.name) as task_name
 			FROM notes n

src/lib/queries/tasks.js

@@ -1,5 +1,6 @@
 import db from "../db.js";
 import { addNoteToTask } from "./notes.js";
+import { getUserLanguage, serverT, translateStatus, translatePriority } from "../serverTranslations.js";
 
 // Get all task templates (for dropdown selection)
 export function getAllTaskTemplates() {
@@ -182,8 +183,10 @@ export function updateProjectTaskStatus(taskId, status, userId = null) {
 
 	// Add system note for status change (only if status actually changed)
 	if (result.changes > 0 && oldStatus !== status) {
-		const taskName = currentTask.task_name || "Unknown task";
-		const logMessage = `Status changed from "${oldStatus}" to "${status}"`;
+		const language = getUserLanguage(); // Default to Polish for now
+		const fromStatus = translateStatus(oldStatus, language);
+		const toStatus = translateStatus(status, language);
+		const logMessage = `${serverT("Status changed from", language)} "${fromStatus}" ${serverT("to", language)} "${toStatus}"`;
 		addNoteToTask(taskId, logMessage, true, userId);
 	}
 
@@ -359,41 +362,48 @@ export function updateProjectTask(taskId, updates, userId = null) {
 
 	// Log the update
 	if (userId) {
+		const language = getUserLanguage(); // Default to Polish for now
 		const changes = [];
+		
 		if (
 			updates.priority !== undefined &&
 			updates.priority !== currentTask.priority
 		) {
+			const oldPriority = translatePriority(currentTask.priority, language) || serverT("None", language);
+			const newPriority = translatePriority(updates.priority, language) || serverT("None", language);
 			changes.push(
-				`Priority: ${currentTask.priority || "None"} → ${
-					updates.priority || "None"
-				}`
+				`${serverT("Priority", language)}: ${oldPriority} → ${newPriority}`
 			);
 		}
+		
 		if (updates.status !== undefined && updates.status !== currentTask.status) {
+			const oldStatus = translateStatus(currentTask.status, language) || serverT("None", language);
+			const newStatus = translateStatus(updates.status, language) || serverT("None", language);
 			changes.push(
-				`Status: ${currentTask.status || "None"} → ${updates.status || "None"}`
+				`${serverT("Status", language)}: ${oldStatus} → ${newStatus}`
 			);
 		}
+		
 		if (
 			updates.assigned_to !== undefined &&
 			updates.assigned_to !== currentTask.assigned_to
 		) {
-			changes.push(`Assignment updated`);
+			changes.push(serverT("Assignment updated", language));
 		}
+		
 		if (
 			updates.date_started !== undefined &&
 			updates.date_started !== currentTask.date_started
 		) {
+			const oldDate = currentTask.date_started || serverT("None", language);
+			const newDate = updates.date_started || serverT("None", language);
 			changes.push(
-				`Date started: ${currentTask.date_started || "None"} → ${
-					updates.date_started || "None"
-				}`
+				`${serverT("Date started", language)}: ${oldDate} → ${newDate}`
 			);
 		}
 
 		if (changes.length > 0) {
-			const logMessage = `Task updated: ${changes.join(", ")}`;
+			const logMessage = `${serverT("Task updated", language)}: ${changes.join(", ")}`;
 			addNoteToTask(taskId, logMessage, true, userId);
 		}
 	}

src/lib/serverTranslations.js

@@ -0,0 +1,79 @@
+// Server-side translations for system messages
+// This is separate from the client-side translation system
+
+const serverTranslations = {
+  pl: {
+    "Status changed from": "Status zmieniony z",
+    "to": "na",
+    "Priority": "Priorytet",
+    "Status": "Status", 
+    "Assignment updated": "Przypisanie zaktualizowane",
+    "Date started": "Data rozpoczęcia",
+    "None": "Brak",
+    "Task updated": "Zadanie zaktualizowane",
+    "pending": "oczekujące",
+    "in_progress": "w trakcie", 
+    "completed": "ukończone",
+    "cancelled": "anulowane",
+    "on_hold": "wstrzymane",
+    "low": "niski",
+    "normal": "normalny",
+    "medium": "średni", 
+    "high": "wysoki",
+    "urgent": "pilny"
+  },
+  en: {
+    "Status changed from": "Status changed from",
+    "to": "to",
+    "Priority": "Priority",
+    "Status": "Status",
+    "Assignment updated": "Assignment updated", 
+    "Date started": "Date started",
+    "None": "None",
+    "Task updated": "Task updated",
+    "pending": "pending",
+    "in_progress": "in_progress",
+    "completed": "completed", 
+    "cancelled": "cancelled",
+    "on_hold": "on_hold",
+    "low": "low",
+    "normal": "normal",
+    "medium": "medium",
+    "high": "high", 
+    "urgent": "urgent"
+  }
+};
+
+// Get user's preferred language from request headers or default to Polish
+export function getUserLanguage(req = null) {
+  // For now, default to Polish. In the future, this could be determined from:
+  // - Request headers (Accept-Language)
+  // - User profile settings
+  // - Session data
+  return 'pl';
+}
+
+// Translate a key for server-side use
+export function serverT(key, language = 'pl') {
+  if (serverTranslations[language] && serverTranslations[language][key]) {
+    return serverTranslations[language][key];
+  }
+  
+  // Fallback to English if Polish not found
+  if (language !== 'en' && serverTranslations.en[key]) {
+    return serverTranslations.en[key];
+  }
+  
+  // Return the key itself if no translation found
+  return key;
+}
+
+// Helper function to translate status values
+export function translateStatus(status, language = 'pl') {
+  return serverT(status, language);
+}
+
+// Helper function to translate priority values  
+export function translatePriority(priority, language = 'pl') {
+  return serverT(priority, language);
+}