Phase 2d: Work-driven auto-connect when work requires a link

[itsniper]

Parent: #51

Requirements

• When work requires a connection, auto-connect without Advanced connect (FR-11.1 / FR-4.4 end-state).
• Until FR-4 commands exist, planning may define an interim “work pending” API or test hook; product end-state is non-empty per-peripheral command queue.
• Integrates with idle (2b) and Approach B (2c).

Acceptance criteria

• Documented way for work to drive connect without Advanced hold
• Auto-connect uses ensure-linked + PoweredOn rules
• Quiet after work → idle path applies
• Tests for auto-connect + idle cycle