Remove NUMAHWPolicy and the libnuma dependency

NUMA CPU/memory pinning is no longer worthwhile: the FPGA DMA buffers are
placed device-local by the kernel (dma_alloc_coherent), the big RAM ring
buffer is random-access (first-touch handles placement), and GPU work is
already spread across all visible devices. So drop the pinning entirely
and with it libnuma.

- Delete NUMAHWPolicy; the only concern worth keeping - GPU selection -
  is done directly via pin_gpu() (round-robin over visible GPUs) in the
  indexer pool and the Lite analysis threads. CPU-only threads
  (FPGA acquire/pedestal/summation/frame-transform) no longer bind
  anything.
- Drop get_gpu_numa_node() (sysfs lookup) - only SelectGPUAndItsNUMA
  used it.
- numa_policy broker setting is deprecated and ignored (kept in the API
  for backward compatibility; warns once on startup).
- Remove NUMA_LIBRARY / numa.h / numaif.h detection from CMake.
- Docs: drop the NUMA dependency, remove the numa_policy config example,
  and document running multiple brokers on disjoint GPUs via
  CUDA_VISIBLE_DEVICES.
- Remove NUMA_GPU_REVIEW.md (the planning note; this work is now done).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

image_analysis/indexing/IndexerThreadPool.cpp

@@ -28,15 +28,11 @@ IndexerThread::IndexerThread(const IndexingSettings &settings, int threadid) {
 
 void IndexerThread::Worker(const IndexingSettings &settings, int threadid) {
     try {
-#ifdef JFJOCH_USE_CUDA
-        auto gpu_count = get_gpu_count();
-        if (gpu_count > 0)
-            NUMAHWPolicy::SelectGPUAndItsNUMA(threadid % gpu_count);
-#endif
+        pin_gpu();
     } catch (const std::exception &e) {
-        spdlog::error("Failed to bind thread to NUMA node: {}", e.what());
+        spdlog::error("Failed to pin to GPU {}", e.what());
     } catch (...) {
-        // NUMA policy errors are not critical and should be ignored for the time being.
+        // GPU pinning errors are not critical and should be ignored for the time being.
     }
 
     std::unique_ptr<Indexer> fft_indexer, ffbidx_indexer, fftw_indexer;