feat(webdav): add complete file system support

- Add nc_webdav_list_directory tool for browsing any NextCloud directory
  - Add nc_webdav_read_file tool with automatic text/binary content handling
  - Add nc_webdav_write_file tool supporting text and base64 binary content
  - Add nc_webdav_create_directory tool for creating directories
  - Add nc_webdav_delete_resource tool for deleting files and directories
  - Extend WebDAV client beyond Notes attachments to general file operations
  - Add XML parsing for WebDAV PROPFIND responses with metadata extraction
  - Improve type annotations throughout codebase for better IDE support
  - Add comprehensive documentation with usage examples

  This transforms the NextCloud MCP server from a limited Notes/Tables tool
  into a full-featured file system interface, enabling complete NextCloud
  file management through LLM interactions.

README.md

@@ -14,6 +14,7 @@ The server provides integration with multiple Nextcloud apps, enabling LLMs to i
 |-----|----------------|-------------|
 | **Notes** | ✅ Full Support | Create, read, update, delete, and search notes. Handle attachments via WebDAV. |
 | **Tables** | ⚠️ Row Operations | Read table schemas and perform CRUD operations on table rows. Table management not yet supported. |
+| **Files (WebDAV)** | ✅ Full Support | Complete file system access - browse directories, read/write files, create/delete resources. |
 
 ## Available Tools
 
@@ -39,6 +40,16 @@ The server provides integration with multiple Nextcloud apps, enabling LLMs to i
 | `nc_tables_update_row` | Update an existing row in a table |
 | `nc_tables_delete_row` | Delete a row from a table |
 
+### WebDAV File System Tools
+
+| Tool | Description |
+|------|-------------|
+| `nc_webdav_list_directory` | List files and directories in any NextCloud path |
+| `nc_webdav_read_file` | Read file content (text files decoded, binary as base64) |
+| `nc_webdav_write_file` | Create or update files in NextCloud |
+| `nc_webdav_create_directory` | Create new directories |
+| `nc_webdav_delete_resource` | Delete files or directories |
+
 ## Available Resources
 
 | Resource | Description |
@@ -47,6 +58,37 @@ The server provides integration with multiple Nextcloud apps, enabling LLMs to i
 | `notes://settings` | Access Notes app settings |
 | `nc://Notes/{note_id}/attachments/{attachment_filename}` | Access attachments for notes |
 
+### WebDAV File System Access
+
+The server provides complete file system access to your NextCloud instance, enabling you to:
+
+- Browse any directory structure
+- Read and write files of any type
+- Create and delete directories
+- Manage your NextCloud files directly through LLM interactions
+
+**Usage Examples:**
+
+```python
+# List files in root directory
+await nc_webdav_list_directory("")
+
+# Browse a specific folder
+await nc_webdav_list_directory("Documents/Projects")
+
+# Read a text file
+content = await nc_webdav_read_file("Documents/readme.txt")
+
+# Create a new directory
+await nc_webdav_create_directory("NewProject/docs")
+
+# Write content to a file
+await nc_webdav_write_file("NewProject/docs/notes.md", "# My Notes\n\nContent here...")
+
+# Delete a file or directory
+await nc_webdav_delete_resource("old_file.txt")
+```
+
 ### Note Attachments
 
 This server supports adding and retrieving note attachments via WebDAV. Please note the following behavior regarding attachments: