v0.3.0b6

Pre-release for notification hot-path and telemetry log validation.

Changes:

• Move per-message Aruba telemetry logging from INFO to DEBUG behind an isEnabledFor guard.
• Cache BLE notification callback dispatch arity at start_notify time, including legacy one-argument callbacks.
• Add an indexed notification dispatch path while preserving service UUID mismatch fallback for SwitchBot/Aruba notifications.
• Add tests for multi-service notification dispatch and legacy notification callback signatures.

Validation:

• 174 pytest tests passing.
• Current worktree privacy scan passed for known sensitive local values.
• Field test reported OK before release.