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.
Simulation core has been replaced with the first design-native model and deterministic engine slice.
Simulation and test projects now target net10.0 because this Linux environment only has the .NET 10 runtime.
Win2D editor still references the removed legacy model and is the next major implementation area.

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.
Added TASKS.md as the required per-commit work tracker.
Removed the legacy integer hazard/effect/hazard plug-in simulation surface.
Added design-native terrain, underground carrier layers, surface hazards, props, leaks, doors, reactor bindings, robot inventory, rule events, validation, serialization, and forecasts.
Added deterministic default balancing values.
Added a first deterministic simulation pipeline for network propagation, consumers, leaks, surface interactions, robot safety, reactor readiness, rule events, and forecasts.
Replaced old tests with design-based simulation tests.
Verified dotnet test tests/ReactorMaintenance.Simulation.Tests/ReactorMaintenance.Simulation.Tests.csproj passes: 11 passed.
Attempted dotnet jb cleanupcode --build=False ...; unavailable in this environment because dotnet-jb is not installed.
Reviewed the first slice and fixed an action-resolution maintainability issue before commit.
Verified git diff --check reports no whitespace errors.

Expand simulation fidelity where the first slice is intentionally simplified: junction branch inference, ambiguity validation, complete pair table coverage, richer rule predicates/effects, and stronger forecast proof cases.
Update the Win2D editor for all authored layers and new runtime inspection.
Add editor workflows for reactor bindings, door edge selection, electricity wall leak faces, rule events, and layer-specific painting.
Update README and any affected docs to reflect the new schema, .NET target, editor controls, and deterministic defaults.
Build the Win2D project on a Windows-capable environment after the editor rewrite.
Add broader tests for junction ratios, ambiguous junctions, all rule event families, serialization edge cases, and editor operations.
Run cleanup when dotnet-jb is available, tests, code review, and iterate until the implementation is clean and maintainable.