#303 Create 3-zone adapter for office visualization

[williamthorsen]

Closes #303

What

Adds a complete spatial adapter pipeline that maps LogicalSceneState to the 3-zone office facility layout (prep area, workshop, governor's office). The pipeline spans 18 new files (10 source, 8 test) implementing types, zone definitions, layout with corridor paths, agent/artifact-to-zone mapping, structural diffing, pixel-space position resolution, transition planning, and an Excalibur OfficeScene with geometric placeholders.

Why

The office visualization needs a spatial layer between the visualization-agnostic LogicalSceneState (from #299) and the rendering engine. This adapter assigns entities to physical zones and desk slots, calculates corridor movement paths between zones, detects state changes across snapshots, and produces animation instructions — all as pure functions that can be tested independently of Excalibur.

Details

Features

• Zone definitions: 3 zones — prep (2 desks), workshop (6 desks), governor's office (1 desk + 3 storage slots) — with tile-space bounds and doorway positions
• Layout: createOfficeLayout() factory providing slotPosition(), zoneCenter(), slotsInZone(), and corridorPath() for all 6 directional zone pairs. Defensive copies on position queries.
• Adapter: mapLogicalToOffice() maps agents by phase (architecture/planning → prep, implementation/review/simplifier/holistic → workshop), orchestrator by status + current phase, and artifacts by delivery status. Reviewer slots assigned by stable sorted-ID index with overflow warning.
• Differ: diffOfficeConfigs() detects orchestrator, agent, artifact, and zone state changes with hasChanges short-circuit
• Position resolver: resolvePositions() maps zone/slot assignments to pixel coordinates via FacilityLayout
• Transition planner: planTransitions() converts diffs into ordered animation instructions (walk, state_change, fade_in, fade_out, artifact_appear, artifact_deliver) with 150ms stagger
• OfficeScene: Excalibur scene wiring the full pipeline with geometric placeholders and error boundary. Positions applied directly (animation playback deferred to Implement office visualization with React canvas and animation #307).

Tests

• 8 test files with comprehensive coverage across all layers (zone definitions, layout, agent zone assignments, logical-to-office adapter, differ, position resolver, transition planner, scene integration)
• Edge cases: reviewer overflow, idle+done zone states, in_transit artifact handling, empty state, corridor path reversal verification