Fix Transmission remote configuration handling

This commit addresses an issue where the Transmission remote setting wasn't properly preserved between install scripts.
Major changes:

- Fixed environment variable sharing between install-script.sh and main-installer.sh
- Added multiple methods to locate and load the .env.install file
- Removed duplicate log message in dependencies-module.sh
- Improved permission handling for the environment file
- Directly export TRANSMISSION_REMOTE variable before launching main-installer.sh

This ensures the user's choice of remote or local Transmission is correctly honored throughout the installation process.

🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>

main-installer.sh

@@ -5,6 +5,12 @@
 # Set script to exit on error
 set -e
 
+# Load installation environment variables if they exist
+if [ -f "$(dirname "$0")/.env.install" ]; then
+  source "$(dirname "$0")/.env.install"
+  echo "Loaded TRANSMISSION_REMOTE=$TRANSMISSION_REMOTE from environment file"
+fi
+
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