Phase 64: managed timer fulfillment vertical

[hotzenplotz5]

Scope

Phase 64 Block 1: complete the managed Timer fulfillment vertical without starting Phase 65.

Current work establishes the backend-neutral native Timer specification, stable VDR managed correlation, CREATE-specific authoritative readback expectation/evidence, fail-closed CREATE verification, and VDR evidence building against complete inventory proof.

Planned in this same PR:

• minimal TimerIntent application entry point
• deterministic primary scheduling into provisioning
• managed CREATE / UPDATE / TOGGLE execution contracts
• normal Control Plane -> Agent -> SuiteBridge native transport wiring
• productive integration of the already accepted safe DELETE path
• durable starting / no-blind-retry / outcome_unknown recovery
• authoritative PRESENT readback for create/update/toggle and complete-inventory ABSENCE for delete
• managed NativeTimerBinding persistence and assignment bound transition
• bounded real yaVDR acceptance before shipped mutation advertisement is opened

Safety constraints

• Timer writes remain closed while this PR is Draft and until exact-candidate yaVDR acceptance passes.
• No blind mutation retry after possible dispatch.
• Backend generation, assignment/binding identity and fingerprints fail closed.
• CREATE reserves stable Suite correlation identities before native dispatch and binds only after authoritative readback.
• Existing Wire fenced native VDR Timer delete mutation #193 native DELETE implementation is not refactored unnecessarily.
• No reassignment/failover, broad Timer UI, streaming, or SearchTimer redesign in this block.

This is intentionally one coherent Block-1 PR rather than a stack of mechanical micro-PRs.