feat: add memory analysis endpoint and enhance AI multi-command support}
- Add memory-analysis.mjs socket handler that scans keys via pipeline to collect type distribution, memory usage per prefix, top keys by size, TTL/expiration overview, and Redis server/memory info - Update AI prompt to support multi-command output separated by ---, preferring multiple commands over EVAL for multi-step operations - Add parseAiResponse helper to handle new --- separator format with fallback to legacy single-line parsing - Improve EVAL guidance to require real line breaks instead of escape sequences to prevent Lua compilation errors - Add connection guard checks in set-monitor and set-subscription handlers to return an error when not connected to Redis - Bump version to 2026.4.311