Introduces automatic creation of a self-documenting startup.json file on first startup, with example path configurations for Linux, Windows, and portable setups. Adds preset database configurations to database.xml for easy switching between SQLite and PostgreSQL. Refactors database config classes for XML serialization compatibility and ensures database.xml is never empty. Comprehensive documentation and migration guides included.
Added support for configuring all major Jellyfin paths (data, config, cache, log, temp, web) via a `startup.json` file, with priority after CLI and environment variables. Introduced a new `TempDir` option, configurable through CLI, env var, or config file, with backward-compatible defaults. Refactored path resolution logic to integrate file-based config and ensure directory creation. Updated constructors and CLI options to support temp directory. Improved EF Core migration error handling and logging. Added comprehensive documentation and example config files. All changes are backward compatible.