🔴 CRITICAL: Add Flyway for database migrations

[GitAddRemote]

Problem

Currently using Hibernate ddl-auto=update which is NOT production-safe and can cause data loss. A migration file exists at db/migration/V1__baseline.sql but won't execute without a migration tool.

Solution

1. Add Flyway dependencies to apps/backend/build.gradle.kts:

implementation("org.flywaydb:flyway-core")
implementation("org.flywaydb:flyway-database-postgresql")

2. Update application.yml:

spring:
  jpa:
    hibernate:
      ddl-auto: validate  # Change from 'update'

3. Enable Flyway in application.yml if needed:

spring:
  flyway:
    enabled: true
    baseline-on-migrate: true

4. Verify existing migration runs successfully

Files to Modify

• apps/backend/build.gradle.kts
• apps/backend/src/main/resources/application.yml
• apps/backend/src/main/resources/db/migration/V1__baseline.sql (verify)

Acceptance Criteria

• Flyway dependencies added
• ddl-auto changed to validate
• Application starts successfully with Flyway
• V1__baseline.sql migration executes on clean database
• Existing data not affected on running instance

Priority

🔴 Critical - Must fix before production deployment