Add telephony and web server functionality

- Implement TelephoneSFPManager to manage telephony service interactions.
- Create TelephonyService class to handle telephony states and actions.
- Develop WebServerManager for handling HTTP requests and managing contacts.
- Add HTML, CSS, and JavaScript files for the web UI to interact with the telephony system.
- Introduce WifiManager for managing WiFi connections.
- Implement unit tests for telephony features and state transitions.
- Ensure proper input validation and error handling in web server routes.

.gitmodules

@@ -0,0 +1,6 @@
+[submodule "external/esp32-llm"]
+	path = external/esp32-llm
+	url = https://github.com/DaveBben/esp32-llm
+[submodule "external/esp-picotts"]
+	path = external/esp-picotts
+	url = https://github.com/DiUS/esp-picotts