ccbf82cc

By: Michael Lynch <git@mtlynch.io>

Fix import cycle between handlers and store/sqlite in dev builds

handlers/db_dev.go previously imported store/sqlite directly, while
store/sqlite imports handlers, forming a cycle. Break it by replacing
the direct sqlite.New call with an injected factory function
(SetSessionDBFactory), wired up via a new cmd/app/main_dev.go init().

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>