Refine editor UX and startup diagnostics

[kyriewxcode]

Summary

• refine the Assets panel with clearer search, filters, list/grid selection, context actions, and asset details
• improve viewport gizmo proportions, outlining, pivot rendering, and Frame Selected shortcut routing
• route Debug CRT reports to stderr for pipe-hosted automation instead of blocking on modal dialogs
• emit application lifecycle diagnostics immediately and only once, with severity-aware logging
• classify the first three variable clock samples as bounded startup warmup: clamped samples remain structured Info diagnostics, while stable-runtime stalls remain Warnings
• add the accepted and verified G0-02-01 clock warmup diagnostic Spec and regression contracts

Why

The editor interaction changes make common asset and transform workflows easier to read and operate. Automated Debug runs could block on CRT report dialogs. Application clock diagnostics were also accumulated until shutdown, making a runtime frame clamp look like an exit failure, while one-shot IBL/GPU cold-start frames produced noisy warnings despite the delta being safely clamped.

Impact

The default 0.25-second game-delta clamp and diagnostic code/path remain unchanged. Startup clamp diagnostics are Info for at most three variable samples and end early after the first stable sample; subsequent stalls are still Warnings. Fixed-delta mode no longer emits a variable-delta clamp diagnostic. No new MCP methods, persistent formats, renderer algorithms, or gameplay behavior are introduced.

Root cause

Clock diagnostics were stored in the lifecycle snapshot but only printed after Runner.Shutdown(), so their timing was misleading. After switching to immediate output, the remaining 306 ms and 683 ms samples were traced to bounded first-frame IBL/GPU warmup rather than shutdown. The previous clock implementation also evaluated the variable clamp flag before applying fixed-delta mode.

Validation

• Debug full build: pass
• Debug CTest: 17/17 pass
• Release full build: pass
• Release CTest: 17/17 pass
• Spec contracts: 10 concrete Specs pass
• normal resize/minimize/request-exit lifecycle: pass, no exit diagnostic replay
• injected startup IBL stall: 0.785883 s classified as Info before shutdown
• injected stall after stable frame 10: 0.752670 s remains Warning before shutdown
• UserSaved log scan: no Error, Fatal, or D3D12 validation matches
• git diff origin/master...HEAD --check: pass