Summary

Implement the HybridStrategy for the pluggable ceremony scheduling system.

Both calendar and task-driven triggers exist on each ceremony. Whichever fires first wins and resets the cadence. Calendar provides a heartbeat floor; task counts provide a throughput ceiling.

Design Reference

See Ceremony Scheduling design page -- "Hybrid (First Wins)" strategy section.

Key Behaviors

• should_fire_ceremony: checks BOTH calendar elapsed time AND task completion count -- returns true if either condition is met, then resets both counters
• should_transition_sprint: returns IN_REVIEW on task completion threshold OR calendar duration boundary -- whichever comes first
• Lifecycle hooks: no-op (stateless, combines calendar + task-driven logic)
• Default velocity calculator: MultiDimensionalVelocityCalculator (pts/sprint primary + secondary dimensions)

Implementation

• New: src/synthorg/engine/workflow/strategies/hybrid.py
• New: tests/unit/engine/workflow/strategies/test_hybrid.py
• Implement CeremonySchedulingStrategy protocol from feat: sprint ceremony runtime scheduler with task-driven cadence support #961

Also implement: MultiDimensionalVelocityCalculator

• New: src/synthorg/engine/workflow/velocity_calculators/multi_dimensional.py
• New: tests/unit/engine/workflow/velocity_calculators/test_multi_dimensional.py
• Primary: pts/sprint, secondary: pts/task, pts/day, completion_ratio

Dependencies

• feat: sprint ceremony runtime scheduler with task-driven cadence support #961 (protocol interfaces + reference implementation)
• feat: calendar ceremony scheduling strategy #969 (CalendarStrategy -- shares calendar-interval logic)