fix: address twentieth round of Copilot PR review feedback

- Fix install rollback: capture registered_commands/registered_skills
  in local vars before try block so rollback uses actual partial
  progress instead of reading from registry (which may not be updated)
- Fix frontmatter body stripping: remove only the single newline after
  the closing fence instead of strip() which could remove intentional
  leading/trailing whitespace from command bodies
- Fix PyYAML warning precision: capture stderr from Python helper and
  check for explicit 'yaml_missing' signal instead of grep heuristic
  that could false-positive on unrelated strategy: fields

Author: mnriem

scripts/bash/common.sh

@@ -423,12 +423,14 @@ except Exception:
                         if [ -f "$manifest" ] && command -v python3 >/dev/null 2>&1; then
                             # Requires PyYAML; falls back to replace/convention if unavailable
                             local result
+                            local py_stderr
+                            py_stderr=$(mktemp)
                             result=$(SPECKIT_MANIFEST="$manifest" SPECKIT_TMPL="$template_name" python3 -c "
 import sys, os
 try:
     import yaml
 except ImportError:
-    print('yaml_missing\treplace\t', file=sys.stderr)
+    print('yaml_missing', file=sys.stderr)
     print('replace\t')
     sys.exit(0)
 try:
@@ -441,16 +443,17 @@ try:
     print('replace\t')
 except Exception:
     print('replace\t')
-" 2>/dev/null)
+" 2>"$py_stderr")
                             local parse_status=$?
                             if [ $parse_status -eq 0 ] && [ -n "$result" ]; then
                                 IFS=$'\t' read -r strategy manifest_file <<< "$result"
                                 strategy=$(printf '%s' "$strategy" | tr '[:upper:]' '[:lower:]')
                             fi
-                            # Warn if PyYAML is missing and preset uses non-default file/strategy
-                            if [ -f "$manifest" ] && grep -q 'strategy:' "$manifest" 2>/dev/null && [ "$strategy" = "replace" ] && [ -z "$manifest_file" ]; then
+                            # Warn only when PyYAML is explicitly missing
+                            if grep -q 'yaml_missing' "$py_stderr" 2>/dev/null; then
                                 echo "Warning: PyYAML not available; composition strategies in $manifest may be ignored" >&2
                             fi
+                            rm -f "$py_stderr"
                         fi
                         # Try manifest file path first, then convention path
                         local candidate=""

scripts/powershell/common.ps1

@@ -423,13 +423,13 @@ function Resolve-TemplateContent {
                     try {
                         # Use Python to parse YAML manifest for strategy and file path
                         $pyArgs = if ($pyCmd.Count -gt 1) { $pyCmd[1..($pyCmd.Count-1)] } else { @() }
+                        $pyStderr = $null
                         $stratResult = & $pyCmd[0] @pyArgs -c @"
 import sys
 try:
     import yaml
 except ImportError:
-    import sys as _s
-    print('yaml_missing', file=_s.stderr)
+    print('yaml_missing', file=sys.stderr)
     print('replace\t')
     sys.exit(0)
 try:
@@ -442,17 +442,22 @@ try:
     print('replace\t')
 except Exception:
     print('replace\t')
-"@ $manifest $TemplateName 2>$null
+"@ $manifest $TemplateName 2>&1 | ForEach-Object {
+                            if ($_ -is [System.Management.Automation.ErrorRecord]) {
+                                $pyStderr = $_.ToString()
+                            } else { $_ }
+                        }
                         if ($stratResult) {
                             $parts = $stratResult.Trim() -split "`t", 2
                             $strategy = $parts[0].ToLowerInvariant()
                             if ($parts.Count -gt 1 -and $parts[1]) { $manifestFilePath = $parts[1] }
                         }
+                        # Warn only when PyYAML is explicitly missing
+                        if ($pyStderr -and $pyStderr -match 'yaml_missing') {
+                            Write-Warning "PyYAML not available; composition strategies in $manifest may be ignored"
+                        }
                     } catch {
                         $strategy = 'replace'
-                        if ((Test-Path $manifest) -and (Select-String -Path $manifest -Pattern 'strategy:' -Quiet -ErrorAction SilentlyContinue)) {
-                            Write-Warning "Cannot parse preset manifest $manifest; composition strategies may be ignored"
-                        }
                     }
                 }
                 # Try manifest file path first, then convention path

src/specify_cli/presets.py

@@ -1247,6 +1247,8 @@ def install_from_directory(
             "registered_skills": [],
         })
 
+        registered_commands: Dict[str, List[str]] = {}
+        registered_skills: List[str] = []
         try:
             # Register command overrides with AI agents and persist the result
             # immediately so cleanup can recover even if installation stops
@@ -1264,16 +1266,12 @@ def install_from_directory(
             })
         except Exception:
             # Roll back all side effects: unregister any commands/skills that
-            # were written, remove the copied preset dir, and drop the
-            # registry entry.
-            metadata = self.registry.get(manifest.id)
-            if metadata:
-                rc = metadata.get("registered_commands", {})
-                if rc:
-                    self._unregister_commands(rc)
-                rs = metadata.get("registered_skills", [])
-                if rs:
-                    self._unregister_skills(rs, dest_dir)
+            # were written (using local vars which capture partial progress),
+            # remove the copied preset dir, and drop the registry entry.
+            if registered_commands:
+                self._unregister_commands(registered_commands)
+            if registered_skills:
+                self._unregister_skills(registered_skills, dest_dir)
             if dest_dir.exists():
                 shutil.rmtree(dest_dir)
             self.registry.remove(manifest.id)
@@ -2457,7 +2455,10 @@ def _split_frontmatter(text: str) -> tuple:
             if end == -1:
                 return None, text
             fm_block = text[:end + 3]
-            body = text[end + 3:].strip()
+            body = text[end + 3:]
+            # Remove only the single newline after the closing fence
+            if body.startswith("\n"):
+                body = body[1:]
             return fm_block, body
 
         if is_command: