Update to python 3.14 | Convert to Vite project on Node 24

[ShaneIsrael]

This pull request makes significant updates to both the client and server sides of the application. The most notable changes include migrating the client build system from Create React App (CRA) to Vite, upgrading the Node.js and Python versions in the Docker environment, and improving password security by using stronger hashing algorithms. Additionally, there are several codebase modernizations and environment variable updates to support the new build system.

Build System and Environment Updates

• Migrated the client from Create React App to Vite, updating scripts in package.json, replacing public/index.html with a new index.html, and adding a vite.config.js for Vite-specific configuration. This also includes changes to environment variable usage and proxy settings. [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12]
• Updated the Dockerfile to use Node.js 24 and Python 3.14, and adjusted related commands and dependencies. Python is now installed from the deadsnakes PPA, and symlinks are created for compatibility. [1] [2] [3] [4]

Security and Database Improvements

• Switched password hashing from sha256 to pbkdf2:sha256 for all new users and admin accounts, improving password security. [1] [2] [3]
• Enhanced admin user initialization logic to ensure admin credentials are kept in sync with environment variables, and to handle hash upgrades automatically.

Database Query Modernization

• Replaced deprecated Model.query.get(id) calls with the recommended db.session.get(Model, id) pattern throughout the backend codebase for improved compatibility with newer SQLAlchemy versions. [1] [2] [3] [4] [5] [6] [7] [8]

Environment Variable and Code Cleanups

• Updated all client references from process.env.REACT_APP_* to import.meta.env.VITE_* to align with Vite's environment variable system. [1] [2] [3] [4]
• Cleaned up and clarified environment files for both development and production, removing obsolete variables and updating comments. [1] [2]

These changes collectively modernize the stack, improve security, and set the foundation for faster development and builds.