docs: add Metrics page for the new optional Prometheus support New Metrics.md covers enabling/auth, the fork-safety design (mirroring Scheduling.md's own multi-worker writeup), the full metric reference table, and cardinality rationale for action_type-only labels. Linked from Home.md/_Sidebar.md, cross-referenced from HTTP-API-Reference.md (JSON vs text-exposition routes), Architecture-Internals.md (module map + fork-safety note), Security.md (auth model, what's exposed), and Scheduling.md (reciprocal link -- same category of fork-safety problem, different solution).
docs: document indexed env var support for schedule: Matches the config architecture cleanup in the main repo: schedule: now has an environment variable override via indexed QBT_RULES_SCHEDULE_<N>_CRON /_<N>_CONTEXT variables, replacing the "no override" documentation.
Document the internal cron scheduler (v0.6.0) New Scheduling page covering config, job lifecycle, the no-misfire- catchup behavior, and the multi-worker fork-safety guarantee (verified empirically against a real Gunicorn deployment, not just claimed). Cross-linked from Architecture Internals (module map, request lifecycle, process boundaries) and In-Depth Configuration (new schedule: config.yml section). Claude-Session: https://claude.ai/code/session_01RmGXvFTXNX36azVbVKMHLL