feat: add GitHub Actions workflow and script for generating PR plugins

- Introduced a new script `generate-pr-plugin.sh` to automate the creation of Unraid PR plugin files.
- Added a GitHub Actions workflow `pr-plugin-build.yml` to build and package the plugin when changes are made to the `emhttp` directory.
- The workflow includes steps for checking out code, generating versioning, creating a tarball, and uploading the plugin artifact for PR testing.

.github/scripts/generate-pr-plugin.sh

@@ -0,0 +1,190 @@
+#!/bin/bash
+
+# Generate PR plugin file for Unraid
+# Usage: ./generate-pr-plugin.sh <version> <pr_number> <commit_sha> <tarball_name>
+
+VERSION=$1
+PR_NUMBER=$2
+COMMIT_SHA=$3
+TARBALL_NAME=$4
+
+if [ -z "$VERSION" ] || [ -z "$PR_NUMBER" ] || [ -z "$COMMIT_SHA" ] || [ -z "$TARBALL_NAME" ]; then
+    echo "Usage: $0 <version> <pr_number> <commit_sha> <tarball_name>"
+    exit 1
+fi
+
+PLUGIN_NAME="webgui-pr-${VERSION}.plg"
+TARBALL_SHA256=$(sha256sum "$TARBALL_NAME" | awk '{print $1}')
+
+echo "Generating plugin: $PLUGIN_NAME"
+echo "Tarball SHA256: $TARBALL_SHA256"
+
+cat > "$PLUGIN_NAME" << 'EOF'
+<?xml version='1.0' standalone='yes'?>
+<!DOCTYPE PLUGIN [
+  <!ENTITY name "webgui-pr">
+  <!ENTITY version "VERSION_PLACEHOLDER">
+  <!ENTITY author "unraid">
+  <!ENTITY pluginURL "https://github.com/unraid/webgui">
+  <!ENTITY tarball "TARBALL_PLACEHOLDER">
+  <!ENTITY sha256 "SHA256_PLACEHOLDER">
+  <!ENTITY pr "PR_PLACEHOLDER">
+  <!ENTITY commit "COMMIT_PLACEHOLDER">
+]>
+
+<PLUGIN name="&name;-&version;" 
+        author="&author;" 
+        version="&version;" 
+        pluginURL="&pluginURL;" 
+        min="6.12.0" 
+        icon="wrench"
+        support="&pluginURL;/pull/&pr;">
+
+<CHANGES>
+##&version;
+- Test build for PR #&pr; (commit &commit;)
+- This plugin installs modified files from the PR for testing
+- Original files are backed up and restored upon removal
+</CHANGES>
+
+<!-- Create backup directory -->
+<FILE Run="/bin/bash" Method="install">
+<INLINE>
+<![CDATA[
+echo "===================================="
+echo "WebGUI PR Test Plugin Installation"
+echo "===================================="
+echo "Version: &version;"
+echo "PR: #&pr;"
+echo "Commit: &commit;"
+echo ""
+
+# Create directories
+mkdir -p /boot/config/plugins/&name;
+mkdir -p /boot/config/plugins/&name;/backups
+
+echo "Created plugin directories"
+]]>
+</INLINE>
+</FILE>
+
+<!-- Download tarball -->
+<FILE Name="/boot/config/plugins/&name;/&tarball;">
+<LOCAL>/boot/config/plugins/&tarball;</LOCAL>
+<SHA256>&sha256;</SHA256>
+</FILE>
+
+<!-- Backup and install files -->
+<FILE Run="/bin/bash" Method="install">
+<INLINE>
+<![CDATA[
+BACKUP_DIR="/boot/config/plugins/&name;/backups"
+TARBALL="/boot/config/plugins/&name;/&tarball;"
+MANIFEST="/boot/config/plugins/&name;/installed_files.txt"
+
+echo "Starting file deployment..."
+
+# Clear manifest
+> "$MANIFEST"
+
+# Extract and get file list
+cd /
+tar -tzf "$TARBALL" | while read -r file; do
+    # Skip directories
+    if [[ "$file" == */ ]]; then
+        continue
+    fi
+    
+    # Convert tar path to actual system path
+    SYSTEM_FILE="/${file}"
+    
+    # Check if file exists and backup
+    if [ -f "$SYSTEM_FILE" ]; then
+        BACKUP_FILE="$BACKUP_DIR/$(echo "$file" | tr '/' '_')"
+        echo "Backing up: $SYSTEM_FILE"
+        cp -p "$SYSTEM_FILE" "$BACKUP_FILE"
+        echo "$SYSTEM_FILE|$BACKUP_FILE" >> "$MANIFEST"
+    else
+        echo "$SYSTEM_FILE|NEW" >> "$MANIFEST"
+    fi
+done
+
+# Extract the tarball
+echo ""
+echo "Installing modified files..."
+tar -xzf "$TARBALL" -C /
+
+echo ""
+echo "✅ Installation complete!"
+echo ""
+echo "The following files have been deployed:"
+cat "$MANIFEST" | cut -d'|' -f1 | while read -r file; do
+    echo "  - $file"
+done
+
+echo ""
+echo "⚠️  This is a TEST plugin for PR #&pr;"
+echo "⚠️  Remove this plugin before applying production updates"
+]]>
+</INLINE>
+</FILE>
+
+<!-- Removal script -->
+<FILE Run="/bin/bash" Method="remove">
+<INLINE>
+<![CDATA[
+echo "===================================="
+echo "WebGUI PR Test Plugin Removal"
+echo "===================================="
+echo ""
+
+BACKUP_DIR="/boot/config/plugins/&name;/backups"
+MANIFEST="/boot/config/plugins/&name;/installed_files.txt"
+
+if [ -f "$MANIFEST" ]; then
+    echo "Restoring original files..."
+    
+    while IFS='|' read -r system_file backup_file; do
+        if [ "$backup_file" == "NEW" ]; then
+            # This was a new file, remove it
+            if [ -f "$system_file" ]; then
+                echo "Removing new file: $system_file"
+                rm -f "$system_file"
+            fi
+        else
+            # Restore from backup
+            if [ -f "$backup_file" ]; then
+                echo "Restoring: $system_file"
+                mv -f "$backup_file" "$system_file"
+            fi
+        fi
+    done < "$MANIFEST"
+    
+    echo ""
+    echo "✅ Original files restored"
+else
+    echo "⚠️  No manifest found, cannot restore files"
+fi
+
+# Clean up
+echo "Cleaning up plugin files..."
+rm -rf "/boot/config/plugins/&name;"
+rm -f "/boot/config/plugins/&tarball;"
+
+echo ""
+echo "✅ Plugin removed successfully"
+]]>
+</INLINE>
+</FILE>
+
+</PLUGIN>
+EOF
+
+# Replace placeholders
+sed -i "s/VERSION_PLACEHOLDER/${VERSION}/g" "$PLUGIN_NAME"
+sed -i "s/TARBALL_PLACEHOLDER/${TARBALL_NAME}/g" "$PLUGIN_NAME"
+sed -i "s/SHA256_PLACEHOLDER/${TARBALL_SHA256}/g" "$PLUGIN_NAME"
+sed -i "s/PR_PLACEHOLDER/${PR_NUMBER}/g" "$PLUGIN_NAME"
+sed -i "s/COMMIT_PLACEHOLDER/${COMMIT_SHA}/g" "$PLUGIN_NAME"
+
+echo "Plugin generated: $PLUGIN_NAME"