feat(detector): SQL/migration detector + SQL_ENTITY NodeKind (#48)

[aksOps]

Summary

Implements task #48: a SQL / migration detector under io.github.randomcodespace.iq.detector.sql that extracts schema-level entities from raw SQL DDL and multi-format migration files.

What the detector handles

• Raw SQL (*.sql): CREATE TABLE, CREATE VIEW, CREATE SCHEMA, ALTER TABLE ... ADD COLUMN, CREATE INDEX, inline FOREIGN KEY ... REFERENCES, DROP TABLE (skipped with debug log).
• Flyway (**/V\d+(?:_\d+)*__.+\.sql): parsed as raw SQL with format=flyway and a version parsed from the filename.
• Liquibase XML (**/changelog.xml, **/db.changelog*.xml): <createTable>, <addColumn>, <addForeignKeyConstraint>.
• Liquibase YAML (**/db.changelog*.yml / .yaml): createTable, addForeignKeyConstraint. Regex-based walk to avoid wiring SnakeYAML into the detector.
• Alembic (**/versions/*.py + from alembic or op.create_table marker): op.create_table, op.add_column, op.create_index, op.create_foreign_key.
• Rails (**/db/migrate/<14-digit>_*.rb): create_table, add_column, add_foreign_key.
• Prisma (**/migrations/*/migration.sql): delegates to the raw-SQL path with format=prisma and directory-name version.

A file is only treated as a migration if the path/filename matches one of those discriminators (Alembic additionally requires a content marker) — arbitrary .py, .rb, .xml, .yml files are ignored. The detector is @Component-scoped, stateless, and emits nodes/edges sorted by id for byte-equal determinism across runs.

Enum changes

Added:

• NodeKind.SQL_ENTITY — new. Schema-level table/view/schema. Distinct from the code-level ENTITY (JPA/ORM) kind; the two are deliberately not collapsed.
• EdgeKind.REFERENCES_TABLE — new. Any node (a JPA ENTITY, SQLAlchemy/TypeORM model, a raw-query node, or another SQL_ENTITY) → SQL_ENTITY. Pairs with existing ORM detectors for the "which code references which table" join.

Reused:

• EdgeKind.MIGRATES — MIGRATION → SQL_ENTITY. The existing MIGRATES is unused in production code (only referenced by ModelCoverageTest), so MIGRATES_SCHEMA was not needed.
• NodeKind.MIGRATION — existing; used for the migration-script-level node.

Test delta

• Before: 3278 passing / 31 skipped
• After: 3294 passing / 31 skipped
• New: 16 tests in SqlMigrationDetectorTest
  • Positive: raw SQL table/view/schema, FK REFERENCES_TABLE edge, CREATE INDEX property enrichment, ALTER TABLE ADD COLUMN property enrichment, Flyway version parse, Alembic op.create_table + add_column + create_foreign_key, Liquibase XML changeSet, Liquibase YAML changeSet, Rails create_table + add_column + add_foreign_key, Prisma migration.sql.
  • Negative: plain .py in app/utils.py, arbitrary .github/workflows/ci.yml, empty content, .py under versions/ without the alembic marker.
  • Determinism: DetectorTestUtils.assertDeterministic plus a byte-equal id-list assertion across two runs.

Design call-outs

• ALTER TABLE ADD COLUMN enriches properties (columns_added=csv) rather than creating column child-nodes, to keep graph size reasonable for large schemas. Same for CREATE INDEX (indexes=csv).
• DROP TABLE is skipped with a debug log — the graph models current state, not deletions.
• Liquibase YAML is parsed via regex rather than SnakeYAML in this detector. Lightweight and keeps the detector self-contained; a future revision can swap in StructuredParser if we need nested-key fidelity.
• LayerClassifier: SQL_ENTITY added to INFRA_NODE_KINDS → classified as infra.
• StatsService: left untouched for v1 — no natural category to plug into yet (databases is DATABASE_CONNECTION only; SQL_ENTITY surfaces through the node-kinds / edges-by-kind breakdown in computeGraph). Follow-up when /api/serve consumers need a dedicated schema breakdown.

Test plan

• mvn -B test — 3294 passing, 0 failing, 31 skipped
• Compile clean (mvn -B test-compile)
• New detector registered by Spring classpath scan (no registry edit needed)
• Determinism assertion: byte-equal node-id and edge-id order across two detect() calls

[sonarqubecloud]

Quality Gate failed

Failed conditions
2 Security Hotspots
C Reliability Rating on New Code (required ≥ A)

See analysis details on SonarQube Cloud

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