feat: Add Projects and Folders UI (SimpleNote v2)

- New Projects view (projects.js): Lists all projects with cards
- New ProjectView (projectView.js): Project dashboard with folder tree
- Updated API client: Projects and Folders CRUD methods
- New modals: NewProjectModal, NewFolderModal, MoveToFolderModal
- Edit/Delete project functionality
- Updated navigation: ProjectList -> ProjectView -> FolderView
- Consistent dark theme styling

Changes:
- public/js/views/projects.js (NEW)
- public/js/views/projectView.js (NEW)
- public/js/api.js (added Projects/Folders API methods)
- public/js/app.js (added navigation routes)
- public/js/components/sidebar.js (added Projects link)
- public/css/style.css (added project/folder styles)

public/js/api.js

@@ -115,6 +115,54 @@ class ApiClient {
   getTags() {
     return this.get('/tags');
   }
+
+  // ===== PROJECTS =====
+  getProjects() {
+    return this.get('/projects');
+  }
+
+  getProject(id) {
+    return this.get(`/projects/${id}`);
+  }
+
+  createProject(data) {
+    return this.post('/projects', data);
+  }
+
+  updateProject(id, data) {
+    return this.put(`/projects/${id}`, data);
+  }
+
+  deleteProject(id) {
+    return this.delete(`/projects/${id}`);
+  }
+
+  getProjectTree(id) {
+    return this.get(`/projects/${id}/tree`);
+  }
+
+  // ===== FOLDERS =====
+  getFolders(projectId, parentId = null) {
+    const query = parentId ? `?parentId=${parentId}` : '';
+    return this.get(`/projects/${projectId}/folders${query}`);
+  }
+
+  createFolder(data) {
+    return this.post('/folders', data);
+  }
+
+  updateFolder(id, data) {
+    return this.put(`/folders/${id}`, data);
+  }
+
+  deleteFolder(id) {
+    return this.delete(`/folders/${id}`);
+  }
+
+  // ===== Move document to folder =====
+  moveDocumentToFolder(documentId, folderId) {
+    return this.put(`/documents/${documentId}`, { folderId });
+  }
 }
 
 export const api = new ApiClient();