analyze_topics() iterates session_manager.sessions and reads
session_data.get("history", []) directly. But SessionManager.load_sessions
seeds sessions metadata-only with empty history — messages are loaded
lazily, only when get_session(session_id) is called. So analyze_topics saw
empty history for every session that hadn't been individually opened this
process lifetime and reported total_topics: 0, even when the database held
plenty of matching messages.
Hydrate each candidate session via session_manager.get_session(session_id)
(the existing lazy-load path) before reading its history, after the
owner/archived filters so skipped sessions aren't loaded. Falls back to the
raw cached history when the manager has no get_session (test stubs).
tests/test_topic_analyzer.py: new test_topic_analyzer_hydrates_sessions
seeds a real SQLite DB with a session + message, runs the real
SessionManager (asserting cached history starts empty), then asserts
analyze_topics finds the topic. Fails before this change. The existing
keyword tests now pass an explicit owner to satisfy the owner-required
early return.