VS-12 Summer Big Refactor (Architecture and Maintainability)

[CherryClairette]

What to build

Execute a focused refactor after core map, analysis, and dashboard slices are live. Improve state boundaries, reduce duplication, stabilize contracts between UI and services, and simplify feature extension without changing user-facing behavior.

Acceptance criteria

• Refactor plan identifies top maintainability pain points and target outcomes
• Core behavior from map, analysis, and dashboard remains unchanged
• Technical debt is reduced with measurable code health improvements
• Regression checks pass for critical user journeys
• Team documents new architecture conventions

Blocked by

VS-07 Map Vertical Slice v1 (Base Map + One Premium Layer)
VS-08 Analysis Vertical Slice v1 (One Chart + Filter + Quota Display)
VS-10 Dashboard Vertical Slice v1 (KPI + Activity + Map Summary)