CMM: per-bay path is goCMM "Selected Part Group" UNC, not Shared Data Directory

A capture from a working CMM4 bay showed the goCMM registry holds two
distinct values under HKLM\SOFTWARE\WOW6432Node\General Electric\goCMM:
  Shared Data Directory = C:\geaofi\                  (constant on every bay)
  Selected Part Group   = \\tsgwp00525...\SHARED\...  (the per-bay UNC path)

The prior commit (f6d970c) put the per-bay path into "Shared Data Directory",
which is wrong. Correct that:
- bay-config column shared_data_dir -> part_group
- resolve-cmm-bay-config emits partgroup.txt (was shareddatadir.txt)
- 09-Setup-CMM seeds "Shared Data Directory" to the constant C:\geaofi\ and
  "Selected Part Group" to the per-bay path, converting the friendly S:\...
  form to the \\tsgwp00525.wjs.geaerospace.net\SHARED UNC at apply time.
  Users write grant on the key is unchanged.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

playbook/shopfloor-setup/gea-shopfloor-cmm/09-Setup-CMM.ps1

@@ -238,30 +238,42 @@ foreach ($exe in $pcdmisExes) {
 }
 
 # ============================================================================
-# Step 2.7: Seed goCMM Shared Data Directory + grant Users write on the key
+# Step 2.7: Seed goCMM registry path values + grant Users write on the key
 # ============================================================================
-# goCMM (.NET x86 WPF app) stores its program-source path in the registry at
-# HKLM\SOFTWARE\WOW6432Node\General Electric\goCMM, value "Shared Data
-# Directory" (the folder it browses for *.prg PC-DMIS measurement routines).
-# It is a 32-bit MSI / 32-bit process, so both the install seed and runtime
-# reads land in the WOW6432Node view. Because the value lives in HKLM, a
-# non-admin shopfloor user cannot set it via goCMM's settings UI - and cannot
-# save a "Selected Part Group" switch either (same key). So we do two things
-# here in admin context:
-#   1. Seed "Shared Data Directory" to the per-bay path resolved by
-#      resolve-cmm-bay-config.ps1 (C:\Enrollment\cmm\shareddatadir.txt).
-#   2. Grant BUILTIN\Users write on the key so runtime writes (part-group
-#      switching, or a deliberate path change) succeed without elevation.
-# This mirrors Step 2.5, which grants Users Modify on the install dirs.
+# goCMM (.NET x86 WPF app) stores its config in the registry at
+# HKLM\SOFTWARE\WOW6432Node\General Electric\goCMM (32-bit MSI / 32-bit
+# process, so install seed and runtime reads both land in the WOW6432Node
+# view). A capture from a working CMM4 bay shows the two values that matter:
+#   Shared Data Directory = C:\geaofi\                                  (constant)
+#   Selected Part Group   = \\tsgwp00525.wjs.geaerospace.net\SHARED\CMM\CMM4\Spool  (per-bay UNC)
+# i.e. the PER-BAY program path is "Selected Part Group" (a UNC to the
+# tsgwp00525 SHARED share), and "Shared Data Directory" is the constant local
+# C:\geaofi\. Both live in HKLM, so a non-admin shopfloor user cannot set
+# them (nor save a part-group switch) without elevation. So in admin context
+# we: seed both values, and grant BUILTIN\Users write on the key so runtime
+# switches succeed without UAC. Mirrors Step 2.5 (install-dir ACL grant).
 $goCmmKey = 'HKLM:\SOFTWARE\WOW6432Node\General Electric\goCMM'
 
-# Path may contain internal spaces (e.g. CMM8 "Venture CMM8"). Get-Content
-# + Trim keeps internal spaces; the value is passed as a single -Value arg,
+# Constant local data dir on every bay.
+$goCmmDataDir = 'C:\geaofi\'
+
+# Host that S: maps to. Selected Part Group is stored as a UNC to this host's
+# SHARED share. Kept in one place so a domain/host change is a one-line edit.
+$partGroupShareRoot = '\\tsgwp00525.wjs.geaerospace.net\SHARED'
+
+# Per-bay part group, resolved by resolve-cmm-bay-config.ps1 into
+# C:\Enrollment\cmm\partgroup.txt as a friendly S:\... path. Convert the S:
+# drive prefix to the UNC share root. Get-Content + Trim keeps internal spaces
+# (e.g. CMM8 "Venture CMM8"); the value is passed as a single -Value arg,
 # never through a command line, so the space cannot split the path.
-$sharedDataDir = ''
-$sddFile = 'C:\Enrollment\cmm\shareddatadir.txt'
-if (Test-Path -LiteralPath $sddFile) {
-    $sharedDataDir = (Get-Content -LiteralPath $sddFile -First 1 -EA 0).Trim()
+$partGroup = ''
+$pgFile = 'C:\Enrollment\cmm\partgroup.txt'
+if (Test-Path -LiteralPath $pgFile) {
+    $raw = (Get-Content -LiteralPath $pgFile -First 1 -EA 0).Trim()
+    if ($raw) {
+        # ^S:\  ->  \\host\SHARED\   (case-insensitive). Leave non-S: values as-is.
+        $partGroup = $raw -replace '(?i)^S:\\', "$partGroupShareRoot\"
+    }
 }
 
 if (-not (Test-Path $goCmmKey)) {
@@ -269,15 +281,24 @@ if (-not (Test-Path $goCmmKey)) {
     try { New-Item -Path $goCmmKey -Force | Out-Null } catch { Write-CMMLog "Could not create $goCmmKey : $_" 'WARN' }
 }
 
-if ($sharedDataDir) {
+# Shared Data Directory (constant)
+try {
+    New-ItemProperty -Path $goCmmKey -Name 'Shared Data Directory' -Value $goCmmDataDir -PropertyType String -Force | Out-Null
+    Write-CMMLog "Set goCMM 'Shared Data Directory' = $goCmmDataDir"
+} catch {
+    Write-CMMLog "Failed to set goCMM 'Shared Data Directory': $_" 'WARN'
+}
+
+# Selected Part Group (per-bay UNC)
+if ($partGroup) {
     try {
-        New-ItemProperty -Path $goCmmKey -Name 'Shared Data Directory' -Value $sharedDataDir -PropertyType String -Force | Out-Null
-        Write-CMMLog "Set goCMM 'Shared Data Directory' = $sharedDataDir"
+        New-ItemProperty -Path $goCmmKey -Name 'Selected Part Group' -Value $partGroup -PropertyType String -Force | Out-Null
+        Write-CMMLog "Set goCMM 'Selected Part Group' = $partGroup"
     } catch {
-        Write-CMMLog "Failed to set goCMM 'Shared Data Directory': $_" 'WARN'
+        Write-CMMLog "Failed to set goCMM 'Selected Part Group': $_" 'WARN'
     }
 } else {
-    Write-CMMLog "No shareddatadir.txt (bay not in bay-config, or manual CMM ID) - leaving goCMM path unset" 'WARN'
+    Write-CMMLog "No partgroup.txt (bay not in bay-config, or manual CMM ID) - leaving 'Selected Part Group' unset" 'WARN'
 }
 
 # Grant BUILTIN\Users ReadKey+WriteKey (WriteKey = SetValue + CreateSubKey).