[JayantDevkar]

Problem

Five tests in tests/api/test_set_session_title.py open the real ~/.claude_karma/metadata.db through the title cache, and test_set_title_success runs ensure_schema on it via get_writer_db(). A contributor running the suite on a schema-changing branch migrates their own live DB without noticing (part 1 of #124). #123 isolated claude_base but not karma_base, which is where the DB path comes from.

Changes

• tests/api/conftest.py: a second autouse fixture redirects Settings.karma_base to a per-test temp dir, which covers both the title cache and sqlite_db_path, and resets the writer singleton before and after each test. Test code only.

Verification

A sqlite3.connect spy over the full api suite, recording every path under ~/.claude_karma:

	connections to the real DB
before	5 (the five test_set_session_title tests)
after	0

Full suite without the spy: 1977 passed, 6 skipped in 8.4 s. ruff check tests/ and ruff format --check clean.

Follow-ups

Part 2 of #124 (spawned_at NOT NULL failure in the shells extractor on real JSONL) stays open.