Add missing test coverage for full text search filter

[browniebroke]

Description

• Configure CI to run tests with PostgreSQL, will be useful for Add unaccent to SearchFilter #9385 as well
• Add missing test coverage for full text search

[Copilot]

Pull request overview

This PR adds PostgreSQL-aware CI configuration and introduces new tests to cover DRF’s SearchFilter full-text search (@-prefixed fields), aligning the test suite with upcoming Postgres-specific search behavior (referenced in #9385).

Changes:

• Add PostgreSQL-backed full-text search tests for SearchFilter using a new requires_postgres pytest marker.
• Update test configuration to support DATABASE_URL via dj-database-url, and auto-skip Postgres-only tests when not on PostgreSQL.
• Update GitHub Actions workflow to run the test matrix against a Postgres service.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
tests/test_filters.py	Adds Postgres-only full-text search test coverage and a construct_search regression test for @ prefix.
tests/conftest.py	Adds DATABASE_URL support and a collection-time skip mechanism for Postgres-only tests.
pyproject.toml	Adds dj-database-url test dependency and registers the requires_postgres marker.
.github/workflows/main.yml	Runs CI tests against a Postgres service and sets DATABASE_URL in the job environment.

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[Copilot]

When DATABASE_URL is set, both the default and secondary database aliases are configured with the exact same connection info. On PostgreSQL, Django will attempt to create a separate test database per alias, and identical NAME/settings can cause test database creation/teardown to collide. Configure secondary as a TEST mirror of default (or give it a distinct TEST/NAME) so multi-db tests can run reliably on Postgres.

Suggested change

	databases = {
	'default': dj_database_url.config(),
	'secondary': dj_database_url.config(),
	default_database = dj_database_url.config()
	secondary_database = default_database.copy()
	secondary_database['TEST'] = {'MIRROR': 'default'}
	databases = {
	'default': default_database,
	'secondary': secondary_database,

[Copilot]

This CI step creates the unaccent extension in the postgres database, but Django/pytest will run tests against a newly created test database (e.g. test_postgres), which will not automatically inherit extensions from the original DB. If unaccent is needed for tests, create it in the test DB during test setup (e.g. in a pytest fixture after DB creation) or create it in a template DB used for test DB creation.

Suggested change

	run: PGPASSWORD=postgres psql -h localhost -U postgres -d postgres -c 'CREATE EXTENSION IF NOT EXISTS unaccent;'
	run: |
	PGPASSWORD=postgres psql -h localhost -U postgres -d template1 -c 'CREATE EXTENSION IF NOT EXISTS unaccent;'
	PGPASSWORD=postgres psql -h localhost -U postgres -d postgres -c 'CREATE EXTENSION IF NOT EXISTS unaccent;'