Jellyfin 11.0.0-PostgreSQL PREVIEW: version bump & defaults

- Update version to 11.0.0-PostgreSQL-PREVIEW in assemblies, installer, and build scripts
- Default web directory is now "wwwroot" across all platforms
- Configuration manager now creates .example files if missing
- Set PostgreSQL as default database with sensible options
- Postgres provider ensures database exists before table checks
- Add docs for marker conflict fixes and startup.json path issues
- Version string in logs/UI uses informational version
- Installer output filename and wizard show PREVIEW suffix
- Documentation summarizes version bump and verification steps

jellyfin-setup.iss

@@ -5,7 +5,7 @@
 [Setup]
 ; Basic Application Information
 AppName=Jellyfin Server (PostgreSQL Edition)
-AppVersion=11.0.0
+AppVersion=11.0.0-PostgreSQL-PREVIEW
 AppPublisher=Your Name
 AppPublisherURL=https://your-website.com
 AppSupportURL=https://your-website.com
@@ -14,7 +14,7 @@ DefaultDirName={autopf}\Jellyfin-PostgreSQL
 DefaultGroupName=Jellyfin PostgreSQL
 AllowNoIcons=yes
 OutputDir=installer-output
-OutputBaseFilename=JellyfinSetup-PostgreSQL-11.0.0
+OutputBaseFilename=JellyfinSetup-PostgreSQL-11.0.0-PREVIEW
 Compression=lzma2
 SolidCompression=yes
 ArchitecturesAllowed=x64compatible