Feature/migrate db to neon

[ArchILLtect]

This pull request migrates the project’s database from MySQL to PostgreSQL, with Neon as the production database provider. The changes update the codebase, configuration files, and documentation to support PostgreSQL throughout development, testing, and deployment. Schema scripts and seed data are also adapted for PostgreSQL syntax and conventions.

Database migration to PostgreSQL:

• Updated all database connection logic, JDBC URLs, and Hibernate dialects in SessionFactoryProvider.java, hibernate.cfg.xml, and test configuration files to use PostgreSQL instead of MySQL. [1] [2] [3] [4]
• Replaced MySQL JDBC driver dependency with PostgreSQL in pom.xml. [1] [2]
• Converted schema and seed scripts in cleandb.sql and data.sql to PostgreSQL syntax, including identity columns, enum handling, and unique constraints. [1] [2] [3]

Documentation and deployment updates:

• Revised README.md and docs/deployment.md to describe PostgreSQL usage for dev/test/prod, with Neon as the serverless production database. Includes new instructions for configuring environment variables and JDBC URLs. [1] [2] [3] [4] [5]
• Added guidance for migration from AWS RDS MySQL to Neon PostgreSQL, including schema conversion steps.

Testing and troubleshooting improvements:

• Updated test database properties and error messages to reflect PostgreSQL usage. [1] [2]
• Enhanced troubleshooting documentation for PostgreSQL and Neon-specific issues, including SSL requirements and schema management.

[Copilot]

Pull request overview

This pull request migrates the project's database infrastructure from MySQL to PostgreSQL, using Neon as the serverless production database provider. The migration updates all database connection configurations, SQL schemas, dependency declarations, and documentation to support PostgreSQL throughout the development, testing, and deployment lifecycle.

Changes:

• Replaced MySQL JDBC driver with PostgreSQL driver (version 42.7.7) and updated all Hibernate configurations to use PostgreSQL dialect and connection URLs
• Converted SQL schema scripts from MySQL syntax to PostgreSQL syntax, replacing AUTO_INCREMENT with GENERATED ALWAYS AS IDENTITY, ENUM with VARCHAR + CHECK constraints, and MySQL-specific timestamp updates with standard defaults
• Updated deployment documentation to describe Neon PostgreSQL setup, environment variables, and SSL requirements; revised README to reflect PostgreSQL as the database for all environments

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
src/test/resources/test-db.properties.example	Added PostgreSQL connection template for local testing with proper driver, dialect, and SSL configuration
src/test/resources/cleandb.sql	Converted test schema from MySQL to PostgreSQL syntax (identity columns, constraints, enum handling)
src/test/java/me/nickhanson/codeforge/testutil/Database.java	Updated error message to be database-agnostic
src/main/resources/hibernate.cfg.xml	Changed JDBC driver, dialect, and connection URL from MySQL to PostgreSQL with SSL enabled
src/main/resources/data.sql	Added missing user_id column to INSERT statements for submissions and drill items
src/main/java/me/nickhanson/codeforge/persistence/SessionFactoryProvider.java	Updated default port, JDBC URL format, and driver class to PostgreSQL; changed dialect default
pom.xml	Replaced MySQL connector dependency with PostgreSQL JDBC driver
docs/deployment.md	Revised deployment guide to describe Neon PostgreSQL setup, removed RDS-specific instructions, added migration guidance
README.md	Updated database technology description from MySQL to PostgreSQL/Neon

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[Copilot]

This section references "Spring" properties and "application.yml", but this project uses Hibernate directly without Spring (as documented at the top of the file). Remove or update this section to reflect Hibernate-specific configuration instead of Spring configuration.

[Copilot]

Using GENERATED ALWAYS AS IDENTITY prevents explicit ID insertion, which is correct for these tables. However, if you ever need to insert rows with specific IDs (e.g., for testing or data migration), consider using GENERATED BY DEFAULT AS IDENTITY instead. The current approach is more secure but less flexible.

Suggested change

	id BIGINT GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
	id BIGINT GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,

[Copilot]

The README still contains multiple references to MySQL that need to be updated to PostgreSQL, including:

• "Tests use a local MySQL test database" (line 272)
• "Create a local MySQL test database" section heading (line 274)
• "Ensure MySQL is running locally" (line 279)
• Example connection properties showing MySQL driver and dialect (lines 293-297)

These sections should be updated to reflect the PostgreSQL migration.

[Copilot]

The default JDBC URL uses ssl=true&sslmode=require, which will fail when connecting to a local PostgreSQL instance for development. Local PostgreSQL typically doesn't have SSL configured. Consider detecting localhost connections and disabling SSL for them (e.g., ssl=false when host is "localhost"), while keeping SSL enabled for production. The test-db.properties.example correctly uses ssl=false for local development.

Suggested change

	url = "jdbc:postgresql://" + host + ":" + port + "/" + db
	+ "?ssl=true&sslmode=require";
	boolean isLocalhost = "localhost".equalsIgnoreCase(host) || "127.0.0.1".equals(host);
	String sslParams = isLocalhost ? "?ssl=false" : "?ssl=true&sslmode=require";
	url = "jdbc:postgresql://" + host + ":" + port + "/" + db + sslParams;

[Copilot]

The default JDBC URL includes ssl=true&sslmode=require, but this will fail for local development connections to PostgreSQL. The test-db.properties.example correctly uses ssl=false for local development. Consider making SSL conditional based on the environment (e.g., ssl=false for localhost, ssl=true&sslmode=require for production).

Suggested change

	jdbc:postgresql://${DB_HOST}:5432/${DB_NAME}
	?ssl=true
	&sslmode=require
	jdbc:postgresql://${DB_HOST}:5432/${DB_NAME}${DB_SSL_OPTIONS}

[Copilot]

This documentation still mentions "H2 in-memory DB" for Dev/Test, but the changes migrate to PostgreSQL for all environments. Update this to reflect the new PostgreSQL-based setup for local development and testing.

Suggested change

	- `src/main/resources/hibernate.cfg.xml` points to H2 and sets `hbm2ddl.auto=update`.
	- `src/main/resources/hibernate.cfg.xml` is configured for a local PostgreSQL instance (or Docker) and sets `hbm2ddl.auto=update`.