Add Easy Asterisk Intercom addon with automatic update management

Features:
- Download and install latest Easy Asterisk from GitHub repository
- Automatic version detection using GitHub API
- Smart update checking with user confirmation
- Configuration preservation during updates and reruns
- Backup and restore functionality for configs
- Safe re-run capability without breaking existing setup

Menu changes:
- Added "Install/Update Intercom (Easy Asterisk)" option
- Updated configure_intercom to work with Easy Asterisk installation
- Enhanced configuration interface with file editing support

README updates:
- Added Communication section with Easy Asterisk Intercom
- Documented installation, update, and configuration workflows
- Updated version to 0.9.9
- Added installation locations and management commands

The intercom addon integrates with outis1one/easy-asterisk repository
and follows the pattern of easy-asterisk-v*.sh version files.

Readme.md

@@ -48,9 +48,9 @@ Home/office kiosk for reusing old hardware, displaying:
 # Enable SSH during installation
 
 # Download and run installer
-wget https://github.com/outis1one/ubk/raw/main/install_kiosk_0.9.8.sh
-chmod +x install_kiosk_0.9.8.sh
-./install_kiosk_0.9.8.sh
+wget https://github.com/outis1one/ubk/raw/main/install_kiosk_v0.9.9.sh
+chmod +x install_kiosk_v0.9.9.sh
+./install_kiosk_v0.9.9.sh
 ```
 
 The installer will guide you through configuration during setup.
@@ -112,6 +112,14 @@ The installer will guide you through configuration during setup.
 
 ## Optional Add-ons
 
+### Communication
+- **Easy Asterisk Intercom** - Voice communication and intercom system
+  - Downloads latest version from Easy Asterisk repository
+  - Automatic update detection and installation
+  - Configuration preservation during updates
+  - Full Asterisk PBX integration
+  - SIP/PJSIP support for IP phones and softphones
+
 ### Audio
 - **Lyrion Music Server (LMS)** - Formerly Logitech Media Server
 - **Squeezelite Player** - Network audio player for LMS
@@ -385,15 +393,61 @@ smb://WORKGROUP/COMPUTER/PrinterName
 
 ```bash
 # Run installer script again to access menu
-./install_kiosk_0.9.8.sh
+./install_kiosk_0.9.9.sh
 
 # Menu structure:
 # 1. Core Settings - Sites, WiFi, schedules, passwords, full reinstall, complete uninstall
-# 2. Addons - LMS, CUPS, VNC, VPNs
+# 2. Addons - Easy Asterisk Intercom, LMS, CUPS, VNC, VPNs
 # 3. Advanced - Diagnostics, logs, Electron updates, virtual consoles, emergency hotspot
 # 4. Restart Kiosk Display
 ```
 
+### Installing Easy Asterisk Intercom
+
+The Easy Asterisk Intercom addon provides voice communication capabilities to your kiosk system.
+
+**Access the addon menu:**
+```bash
+./install_kiosk_v0.9.9.sh
+# Select: 2) Manage Addons
+# Then: 2) Install/Update Intercom (Easy Asterisk)
+```
+
+**Features:**
+- **Automatic installation** - Downloads and installs the latest version from the Easy Asterisk repository
+- **Update detection** - Checks for newer versions and prompts to update
+- **Safe re-runs** - Can be run multiple times without breaking existing configurations
+- **Config preservation** - Automatically backs up and restores configurations during updates
+- **Full Asterisk PBX** - Complete telephony features including SIP, extensions, voicemail
+
+**Installation behavior:**
+- **First install:** Downloads latest version from https://github.com/outis1one/easy-asterisk
+- **Already installed (latest):** Prompts to re-run installation (preserves configs)
+- **Update available:** Prompts to update and shows version difference
+- **All scenarios:** Configuration files in `/etc/asterisk/` and installation settings are preserved
+
+**Managing Easy Asterisk:**
+```bash
+# Check installation status
+systemctl status asterisk
+
+# View Asterisk console
+asterisk -rvvv
+
+# Restart Asterisk
+systemctl restart asterisk
+
+# Configure intercom
+./install_kiosk_v0.9.9.sh
+# Select: 2) Manage Addons → 6) Configure Intercom
+```
+
+**Installation location:**
+- Installation files: `/opt/easy-asterisk/`
+- Configuration: `/etc/asterisk/`
+- Version tracking: `/opt/easy-asterisk/.version`
+- Config backups: `/opt/easy-asterisk/config_backup/`
+
 ### Updating Electron
 
 ```bash
@@ -918,12 +972,16 @@ See the LICENSE file in the repository for full terms.
 
 ## Project Status & Future Plans
 
-**Current Version:** 0.9.8 - Named Sites & Navigation Menu
+**Current Version:** 0.9.9 - Easy Asterisk Intercom Integration
+
+**Recent Updates (v0.9.9):**
+- Easy Asterisk Intercom addon with automatic updates
+- Smart version detection and configuration preservation
+- Enhanced addon management system
 
 **Planned Features:**
 - Web-based GUI configuration interface
 - All-in-one ISO installer
-- Voice communication integration (Asterisk/Baresip)
 - Enhanced Raspberry Pi support and testing
 
 **Known Limitations:**
@@ -960,5 +1018,5 @@ Special thanks to the maintainers of all upstream projects that make UBK possibl
 
 ---
 
-*Last Updated: December 2, 2025*
-*Version: 0.9.8*
+*Last Updated: December 10, 2025*
+*Version: 0.9.9*