Tattoo test bed: Quaternius v3-v6 bakes + Lena pipeline (bake, de-mirror, re-UV, viewers)

Session 2026-07-23/24 additions on top of the existing Quaternius bed:
- bake_lena.gd: 6-piece bake on QuatSkin Lena (chiefs-mark/iron-spine arms,
  voyagers/storm-bearer legs, star-eye chest, hearth-warmth back); global-axis
  wrap frame + 3cm junction blend kill the elbow split line
- demirror_lena.gd: tri-level split of mirror-shared limb UVs (arms 100%->0%,
  legs 99%->5% crotch-only residual)
- reuv_lena.gd: Quaternius-style semantic re-UV (16 islands, cylinder limbs +
  cylinder head/torso with planar caps) + texture transfer; fixes armpit/chin/
  cheek planar smears; single 4096 atlas, per-side tattoos native
- main_lena / anim_lena viewers (18 UAL clips, U light toggle) + probes + shots

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

gen-v6/_gen-sleeves-v6.ps1

@@ -0,0 +1,47 @@
+$ErrorActionPreference = 'Stop'
+$ProgressPreference = 'SilentlyContinue'
+if (-not $env:FAL_KEY) { $env:FAL_KEY = [System.Environment]::GetEnvironmentVariable("FAL_KEY","User") }
+if (-not $env:FAL_KEY) { throw "FAL_KEY not set." }
+$auth = @{ Authorization = "Key $env:FAL_KEY" }
+$dir = "C:\Users\CAN\tinqs-ltd\tattoo-test\gen-v6"
+$log = "$dir\_gen-sleeves-v6.log"
+"START $(Get-Date -Format o)" | Out-File $log
+
+# v6 limb sleeves: SPARSE vertical compositions with v3-style negative space.
+# bake_v6.gd wraps these mirrored + aspect-true and samples only a centered
+# strip (arms ~46%, legs ~29% of the width), so the design must live in the
+# central column and breathe: bold isolated motif clusters, lots of parchment.
+$style = "Polynesian / Marquesan TRIBAL tattoo, solid black ink on off-white parchment. Bold black shapes with crisp edges, koru spirals, shark-tooth (niho) notches, sparing dotwork. Confident, elegant linework."
+$fill  = "SPARSE VERTICAL SLEEVE COMPOSITION: one elegant column of 3-4 bold motif clusters flowing top to bottom in the CENTER of the canvas, separated by generous EMPTY parchment gaps. AT LEAST HALF of the canvas stays empty parchment - the design must breathe like a classic Maori arm sleeve. The composition starts at the very TOP EDGE with one strong horizontal terminal band; below it the clusters get smaller and sparser toward the bottom edge. The left and right outer edges of the canvas stay mostly empty."
+$neg   = "No color, no grey shading, no gradients, no photoreal, no 3D, no human figure, no text, no outer border or frame, no vignette, no dense edge-to-edge pattern fill, no background texture."
+
+$jobs = @(
+  @{ part="arm_r"; mark="chiefs-mark";      d="Theme - CHIEF'S CREST: the terminal band is a spearhead crown with a short fan of broad rays; below it one large koru spiral cluster, then a slim niho tooth band, then one small isolated spiral near the bottom." }
+  @{ part="arm_l"; mark="iron-spine";       d="Theme - IRON SPINE (warrior): the terminal band is a row of interlocked spearhead chevrons; below it two bold crossed spears with barbed heads as the main motif, then a slim shark-tooth band, then one small chevron mark near the bottom." }
+  @{ part="leg_r"; mark="voyagers-current"; d="Theme - VOYAGER'S CURRENT (ocean): the terminal band is a row of wave scrolls; below it one large curling koru wave as the main motif, then a slim flowing current line with a single spiral eddy, then one small wave mark near the bottom." }
+  @{ part="leg_l"; mark="storm-bearer";     d="Theme - STORM BEARER: the terminal band is a row of storm-cloud koru scrolls; below it one bold jagged lightning bolt as the main motif, then a slim zigzag rain band, then one small bolt mark near the bottom." }
+)
+
+$perImage = 0.17  # GPT Image 2, quality=high (estimate)
+$runCost = 0.0; $ok = 0; $fail = 0; $skip = 0
+foreach ($j in $jobs) {
+  $name = "v6_$($j.part)_$($j.mark)"
+  $path = "$dir\$name.png"
+  if (Test-Path $path) { $skip++; "SKIP $name (exists)" | Tee-Object -FilePath $log -Append | Out-Null; continue }
+  Write-Host "=== $name ===" -ForegroundColor Cyan
+  $prompt = "$style`n$fill`n$($j.d)`nSTRICT: $neg"
+  try {
+    $body = @{ prompt=$prompt; image_size="portrait_4_3"; quality="high"; num_images=1 } | ConvertTo-Json -Depth 6 -Compress
+    $resp = Invoke-RestMethod -Method Post -Uri "https://fal.run/openai/gpt-image-2" -Headers $auth -ContentType 'application/json' -Body $body -TimeoutSec 600
+    Invoke-WebRequest -Uri $resp.images[0].url -OutFile $path -TimeoutSec 300
+    $runCost += $perImage; $ok++
+    "OK   $name" | Tee-Object -FilePath $log -Append | Out-Null
+    Write-Host "  OK" -ForegroundColor Green
+  } catch {
+    $fail++
+    "FAIL $name : $($_.Exception.Message) $($_.ErrorDetails.Message)" | Tee-Object -FilePath $log -Append | Out-Null
+    Write-Host "  FAIL: $($_.Exception.Message)" -ForegroundColor Red
+  }
+}
+"DONE ok=$ok fail=$fail skip=$skip RUN_COST_USD=$([math]::Round($runCost,2)) $(Get-Date -Format o)" | Tee-Object -FilePath $log -Append
+Write-Host ("RUN_COST_USD={0:N2}  ok={1} fail={2} skip={3}" -f $runCost,$ok,$fail,$skip) -ForegroundColor Yellow