manifest v6.6.1

🐛 Patch Changes

• 9d3f743: Stop recording Railway and proxy noise headers on every message. Headers injected by the hosting edge (x-railway-, x-forwarded-, x-real-ip, etc.) are dropped before storage, so the message Headers tab only shows headers the agent actually sent.
• 1173e30: Performance: bound the public usage-stats aggregations, add a composite (key_prefix, is_active) index for agent-key auth lookups, reuse uPlot chart instances in place on data refresh instead of rebuilding them, and memoize the message log's feedback overrides.