Add session context, shell configuration, and transparent I/O recording
design notes based on exploration of available SSH library context and
forward-planning for session replay (phase 2.3).
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Adds persistent storage using modernc.org/sqlite (pure Go). Login
attempts are deduplicated by (username, password, ip) with counts.
Sessions and session logs are tracked with UUID IDs. Includes embedded
SQL migrations, configurable retention with background pruning, and
an in-memory store for tests.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
