docs: record the unmeasured CPU-side recipe-diff candidates (HSA knobs, OMP_NUM_THREADS)

All six HSA names verified real by string presence in libhsa-runtime64.so, so
they are knobs and not no-ops — but none is shipped without its own A/B.

serverAppConfigs-docs/log.md

@@ -1170,6 +1170,14 @@ every restart since the cutover.
     list; measured, it is **not** a gap here — capture is 3 PIECEWISE + 2 FULL
     graphs, `Graph capturing finished in 3 secs, took 0.31 GiB` (0.11 GiB on the
     lighter rank). No 15-52-size ladder to cut.
+  - *Not acted on — measured candidates, none shipped (no bench window; these
+    are CPU-side and our decode is gather-bound, so a spin-wait stealing cores
+    from the gather threads is plausible but unproven):* `OMP_NUM_THREADS=8`
+    (defaults to all 16 logical CPUs on this 7700X), `HSA_ENABLE_INTERRUPT=1`,
+    `HSA_ENABLE_MWAITX=1`, `HSA_ENABLE_SDMA`, `HSA_NO_SCRATCH_RECLAIM`,
+    `HSA_ENABLE_IPC_MODE_LEGACY`. All six HSA names verified real — the literals
+    are read out of `/opt/rocm/core-10.0/lib/libhsa-runtime64.so` — so they are
+    knobs, not no-ops; any of them needs its own A/B before shipping.
   - *Deliberate divergence, keep ours:* no MTP (the recipe has it; measured
     fastest here), `qwen3_xml` vs `qwen3_coder` (ours verified live), no
     `--override-generation-config` (server-side sampling defaults), published