fix(dx12): reconcile resource states across submissions

[besmpl]

Summary

• track first-use and final resource states per command buffer, then reconcile them in submission order with queue-local preamble barriers
• retain preamble allocators, command lists, staging resources, and explicit destination COM references until a trustworthy fence or safe terminal teardown
• handle 2D-array and padded 3D buffer/texture copies with exact D3D12 footprints, including block-compressed rows
• make packed depth/stencil SRV, DSV, clear, and companion-plane transitions agree, with complete descriptor-allocation rollback

This replaces the narrower but unsound draft #259. The DX12 indirect-argument ABI correction remains isolated in #258.

Why

Recording-time currentState is not authoritative when command buffers are recorded independently and submitted later or in a different order. The queue now owns scheduled state, plans non-mutating reconciliation barriers immediately before each command buffer, and commits final state only after execution is handed to D3D12.

Verification

• CGO_ENABLED=0 go test ./...
• GOOS=windows GOARCH=amd64 CGO_ENABLED=0 go test -exec=true ./...
• focused Windows amd64 and 386 cross-compilation for hal/dx12 and hal/dx12/d3d12
• git diff --check
• two independent read-only reviews of state/copy/view correctness and queue/COM lifetime

Remaining validation

This was developed on macOS, so native Windows execution and D3D12 debug-layer validation have not run yet. The PR is draft until that hardware evidence is available.