Feature: New database schema for research management

[Brad-Edwards]

Description

Create fresh Flyway migration scripts for the new research management database schema, replacing the old requirements schema.

Scope

• Create migration to drop old requirements tables (Requirement, RequirementRelation, TraceabilityLink, and related tables)
• Create new tables:
  • papers: Research papers with metadata (title, authors, abstract, DOI, publication date, journal, etc.)
  • citations: Citation relationships between papers
  • experiments: Experiments with lifecycle status tracking
  • research_notes: Research notes with type classification
  • research_links: Cross-entity links between papers, experiments, and notes
• Add appropriate indexes for common query patterns
• Add foreign key constraints and cascading rules

Acceptance Criteria

• Flyway migrations run cleanly on a fresh database
• Flyway migrations run cleanly on an existing database (upgrade path)
• All new tables created with proper constraints
• Indexes added for common queries (search by title, DOI, status, etc.)
• Foreign key relationships properly defined
• Migration ordering is correct