Improve GPU compatibility, RDNA2 kernels and startup diagnostics

- Match render/compute adapters and gate RR models by GPU capabilities
- Add RDNA2 native texture kernels and fix FP16 rounding
- Harden model builds, cache validation and packaging
- Add startup tracing, timeouts, documentation and regression tests

docs/architecture.md

@@ -112,6 +112,8 @@ OptiScaler 0.9.4 checks a relative `NvngxPath` against the process working direc
 
 ## Logs
 
+For startup stalls, GPU resets and model-build failures, see [Linux startup diagnostics](linux-startup-diagnostics.md).
+
 The launcher writes each run's logs to `~/.cache/d4r-dlss-captures/game-<exe>-<time>/`. `d4r_nvngx.log` holds the shim's log. With `[Debug] Profile = true` it measures stage timings every frame and records sampled `D4R_PROFILE` lines. `ProfileLogEvery = 60` (the default) logs the first five frames and then every 60th frame; set it to `1` to log every frame, or another positive integer for a different interval. Restart the game after changing it. `D4R_PROFILE_LOG_EVERY` overrides the INI setting. FSR RR stage summaries average that many completed GPU samples; native Vulkan profiling uses the same log interval. Sampling reduces log writes while retaining profiling measurements and per-frame throughput intervals. `D4R_PROFILE_LOG=0` suppresses timing rows and FSR RR summaries.
 
 Output completion uses event queries with 200 us NtDelayExecution sleeps by default. `D4R_SHIM_BLOCKING_SYNC = 0`