docs(perf #N6.1): apply final-review fixes — spec, baseline doc, issue #55

Final code review of slice 1 flagged one Important issue (the spec's
"zero cost when off" claim for the surface-dump path is technically
violated — _uploadMetadata always writes one dict entry per upload
regardless of env var) plus minor doc/consistency gaps. Applied:

1. Spec §5 "Cost when off": dropped the "Zero" claim; replaced with
   "Negligible — one Dictionary write per upload (~30-50 KB at Holtburg)
   plus a hash-table write per upload. Expensive work (file I/O,
   histogram construction) is still env-gated." This matches reality.

2. Baseline doc §5: rewrote from "Raw logs (scratch, can be deleted)"
   referencing files that were never preserved in this worktree, to
   "Reproducing the measurements" with the actual PowerShell launch
   commands. Honest about the raw logs not being kept; the captured
   medians in section 2 are the canonical record.

3. New issue #55 filed in docs/ISSUES.md — static-entity slow path
   reports ~1.45M meshMissing/5s at r4 standstill, drops to ~0 when
   walking. LOW severity (no visible regression), hypothesis points
   at a "permanently-missing entity gets re-classified every frame"
   pattern that Tier 1 cache doesn't cover.

4. Roadmap shipped table: renamed "N.6.1" row to "N.6 slice 1" to
   match every other artifact's naming. Search-discoverability fix.

None of these change the slice's conclusion or next-phase
recommendation (C.1.5 first, then reduced-scope slice 2).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/plans/2026-05-11-phase-n6-perf-baseline.md

@@ -165,14 +165,29 @@ default N₁=4; worth revisiting if a future quality preset wants N₁=8 as defa
 cpu_us median > 5,000 µs or gpu_us p95 > 8,000 µs, re-open the escalation question.
 Otherwise, hold the C.1.5 → reduced-slice-2 sequence.
 
-## §5. Raw logs
+## §5. Reproducing the measurements
 
-Scratch logs from this measurement run (not committed; can be deleted once the doc is
-reviewed):
+Raw `[WB-DIAG]` output from each run was inspected live during measurement and the
+median of the last three steady-state lines from each scenario was transcribed into §2.
+The raw launch logs were not preserved — the captured medians in §2 are the canonical
+record. To reproduce on the same hardware:
 
-- `baseline-r4-stand.log`, `baseline-r4-walk.log`
-- `baseline-r8-stand.log`, `baseline-r8-walk.log`
-- `baseline-r12-stand.log`, `baseline-r12-walk.log`
-- `baseline-surfaces.log` (launch log for `ACDREAM_DUMP_SURFACES=1` run)
-- `baseline-surfaces.txt` (copy of `%LOCALAPPDATA%\acdream\n6-surfaces.txt`)
-- `task1-verify.log` (Task 1 manual verification log)
+```powershell
+$env:ACDREAM_DAT_DIR   = "$env:USERPROFILE\Documents\Asheron's Call"
+$env:ACDREAM_LIVE      = "1"
+$env:ACDREAM_TEST_HOST = "127.0.0.1"
+$env:ACDREAM_TEST_PORT = "9000"
+$env:ACDREAM_TEST_USER = "testaccount"
+$env:ACDREAM_TEST_PASS = "testpassword"
+$env:ACDREAM_WB_DIAG   = "1"
+$env:ACDREAM_STREAM_RADIUS = "4"  # or 8, 12
+dotnet run --project src\AcDream.App\AcDream.App.csproj --no-build -c Debug 2>&1 | Tee-Object -FilePath "baseline.log"
+```
+
+Stand still for ~30 s at the target radius (60 s at radius 12 to let streaming settle),
+or walk N→E→S→W across one landblock. Then `Select-String -Path baseline.log -Pattern
+"\[WB-DIAG\]" | Select-Object -Last 3` captures the steady-state numbers.
+
+For the surface histogram, also set `$env:ACDREAM_DUMP_SURFACES = "1"`, stay in-world
+~30 s after streaming has loaded ≥100 textures (the cache-size gate), then read
+`$env:LOCALAPPDATA\acdream\n6-surfaces.txt`.