Add filesystem scan trigger and version badge features

Implements optional filesystem scan triggering for Plex and Audiobookshelf after file organization, with new settings in the admin UI, setup wizard, and API. Updates documentation to reflect scan trigger options and improved file organization/cleanup logic. Refactors dropdown menus to use smart positioning and portals for better UX. Adds a version API route and a VersionBadge component to display build info in the header. Updates Docker build to inject version metadata.

dockerfile.unified

@@ -2,6 +2,10 @@
 # Single container with PostgreSQL, Redis, and Next.js app
 # Designed for easy deployment with minimal configuration
 
+# Build arguments for version info
+ARG GIT_COMMIT=unknown
+ARG BUILD_DATE=unknown
+
 # Start from debian base with node preinstalled
 FROM node:20-bookworm AS base
 
@@ -45,6 +49,12 @@ COPY . .
 ENV DATABASE_URL="postgresql://dummy:dummy@localhost:5432/dummy?schema=public"
 RUN npx prisma generate
 
+# Set version environment variables for build and runtime
+ENV NEXT_PUBLIC_GIT_COMMIT=${GIT_COMMIT}
+ENV NEXT_PUBLIC_BUILD_DATE=${BUILD_DATE}
+ENV APP_VERSION=${GIT_COMMIT}
+ENV BUILD_DATE=${BUILD_DATE}
+
 # Build Next.js application
 ENV NEXT_TELEMETRY_DISABLED=1
 ENV NODE_ENV=production