fix(docs): address review findings — accuracy, consistency, completeness

- architecture.md: fix kernel param math to match actual computed values,
  use cardN placeholder in sysfs paths, clarify system_ram_kb is OS-visible
- benchmarking.md: normalize flags to -ngl 99 / -mmp 0 (matching code),
  add llama-rocm7-nightlies backend
- CLAUDE.md: clarify HSA_OVERRIDE_GFX_VERSION is set in containers not
  scripts, fix lib sourcing description, specify which scripts need root
- detect.sh: document detect_cpu_cores returns threads not cores
- troubleshooting.md: add link to references.md
- README.md: remove unsupported Fedora 42 claim, describe configs/ content

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

README.md

@@ -84,7 +84,7 @@ See [docs/optimization.md](docs/optimization.md) for the full walkthrough with e
 bin/            Entry points (audit, monitor, benchmark, optimize)
 lib/            Shared bash libraries (common, detect, format)
 scripts/        Implementation organized by function
-configs/        Reference configuration templates
+configs/        Reference configuration (grub-cmdline.conf with recommended kernel params)
 data/           Runtime output: audits, benchmarks, logs, backups (gitignored)
 docs/           Technical documentation
 ```
@@ -93,7 +93,7 @@ See [docs/architecture.md](docs/architecture.md) for the full architecture, data
 
 ## Requirements
 
-- **OS**: Fedora 43 (tested), Fedora 42+ should work
+- **OS**: Fedora 43 (tested). Requires kernel >= 6.18.4
 - **Hardware**: AMD Strix Halo (Ryzen AI MAX / MAX+) with RDNA 3.5 iGPU
 - **Tools**: `bc`, `python3`, `tmux`, `podman`, `toolbox`
 - **Optional**: `amdgpu_top` (installed via `make monitor-install`), `huggingface-cli` (for model downloads)