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+# Reactor Maintenance Rewrite Tasks
+
+## Current State
+
+- Branch: `design-rewrite`
+- Scope approved: implement `docs/design.md` end-to-end with deterministic defaults and no backward compatibility.
+- Existing implementation is the previous combined-cell integer simulation and editor. It will be replaced instead of migrated.
+- First commit establishes this tracker only.
+
+## Completed Work
+
+- Read project instructions, Linux instructions, code style, and `docs/design.md`.
+- Confirmed deterministic balance defaults should be chosen during implementation.
+- Confirmed a full Win2D editor is required.
+- Created branch `design-rewrite`.
+
+## Current Work
+
+- Establish task tracking before code changes.
+
+## Future Work
+
+1. Replace the simulation domain model with terrain, underground carrier layers, props, leaks, doors, inventory, reactor bindings, rule events, forecasts, and float-valued runtime state.
+2. Replace balancing with deterministic defaults for all values named by the design.
+3. Implement validation errors and warnings from the design.
+4. Implement the turn pipeline: actions, runtime validation, rule events, network propagation, consumers, leak injection, surface interactions, robot safety, reactor state, event advancement, and forecasts.
+5. Implement player actions and editor operations for the new model.
+6. Replace serialization with a schema-valid current format only.
+7. Update the Win2D editor for all authored layers and new runtime inspection.
+8. Replace tests with design-based behavior coverage.
+9. Update documentation to reflect the new implementation.
+10. Run cleanup, tests, code review, and iterate until the implementation is clean and maintainable.