Add dev/prod environments with TrueNAS Docker production deploy.

Split PostgreSQL into gallery_dev and gallery_prod, add Docker/Gitea deploy tooling,
SMB image sync, pgAdmin split script, dev:web on Keenetic :5173, and operator docs.

Co-authored-by: Cursor <cursoragent@cursor.com>

infra/docker/save-for-truenas.ps1

@@ -0,0 +1,17 @@
+# Save image to tar for fast SMB copy to TrueNAS (offline registry bypass).
+param(
+    [string]$Tag = "latest",
+    [string]$OutFile = "gallery-web.tar"
+)
+
+$ErrorActionPreference = "Stop"
+$Image = "gitea.mysuperlab.netcraze.pro/danilka/gallery-web:${Tag}"
+
+Write-Host "Saving $Image to $OutFile ..."
+docker save -o $OutFile $Image
+$sizeMb = [math]::Round((Get-Item $OutFile).Length / 1MB, 1)
+Write-Host "Saved $OutFile ($sizeMb MB)"
+Write-Host ""
+Write-Host "On TrueNAS shell:"
+Write-Host "  sudo docker load -i /path/to/$OutFile"
+Write-Host "  sudo docker tag gitea.mysuperlab.netcraze.pro/danilka/gallery-web:$Tag gitea.mysuperlab.netcraze.pro/danilka/gallery-web:latest"