feat: Wave B runtime mode selection, 8-vCPU DEV routing, combat optimizations, and 2026-09-04 handoff

[flashls1]

Overview

This PR delivers the complete Wave B runtime mode selection architecture, 8-vCPU DEV mode routing, combat optimizations, memory audit receipts, and 2026-09-04 agent handoff documentation for TFTMAC on Apple Silicon M4.

Key Changes

1. 8-vCPU DEV Mode Routing (RuntimeModeAuthority.swift):
   • Routes 8 vCPUs (-cores 8, hw.cpu.ncore = 8) to the guest VM in DEV mode (.advancedDiagnostics), absorbing 510% combat load surges while preserving 2 dedicated cores for macOS WindowServer and Metal rendering.
   • Preserves protected Control release at 6 vCPUs.
2. UE4 In-Game Combat Optimizations (TFTMACRuntime.swift):
   • p.ClothPhysics=0: Disables CPU vertex cloth simulation on 20–30 combat units, saving 5–8 ms of GameThread frame budget during combat.
   • r.DynamicRes.OperationMode=1: Activates dynamic resolution master switch with an 85% safety floor and 16.67 ms frame budget.
   • r.pso.PrecompileThreadPoolSize=2: Restricts PSO worker threads to 2 to eliminate combat threadpool contention.
3. Clean Snapshot Teardown:
   • Issues am force-stop 300 ms prior to adb emu kill, closing active Vulkan device instances and eliminating QEMU UNSUPPORTED_VK_APP snapshot save failure.
4. C++ Native Pipeline Runtime (PipelineEventV1.cpp):
   • Resolved drain race condition with atomic flush_target_write synchronization; verified over 20 consecutive runs.
5. Authoritative SSOT & Documentation:
   • Added AGENT_HANDOFF_2026-09-04.md and settings.md.
   • Updated benchmark.md, facts.md, project.md, dev.md, and synchronized ssot/STACK.lock.yaml / AUTHORITY_INPUTS.sha256.

Validation

• ./scripts/verify-tftmac.command: 55/55 native tests passed (0 failures).
• ./scripts/build-dev-launcher.command: Built and code-signed dist/TFTMAC DEV.app.
• ./scripts/install-desktop-launchers.command: Installed to /Applications/TFTMAC DEV.app and Desktop shortcut.