fix: address fourth round of Copilot PR review feedback

- Use Path.is_relative_to() instead of str.startswith() for proper
  path containment check in _reconcile_composed_commands()
- Fix install rollback to undo all side effects: unregister commands
  and skills, remove copied preset dir before dropping registry entry
- Validate wrap placeholder presence: raise PresetValidationError when
  wrapper content is missing {CORE_TEMPLATE} or $CORE_SCRIPT
- Guard python3 availability in PowerShell Resolve-TemplateContent
  with Get-Command check before invoking
- Handle missing PyYAML gracefully in both bash and PowerShell: check
  'import yaml' explicitly and fall back to replace/convention path

Author: mnriem

scripts/bash/common.sh

@@ -419,9 +419,15 @@ except Exception:
                         local manifest_file=""
                         local manifest="$presets_dir/$preset_id/preset.yml"
                         if [ -f "$manifest" ] && command -v python3 >/dev/null 2>&1; then
+                            # Requires PyYAML; falls back to replace/convention if unavailable
                             local result
                             result=$(SPECKIT_MANIFEST="$manifest" SPECKIT_TMPL="$template_name" python3 -c "
-import yaml, sys, os
+import sys, os
+try:
+    import yaml
+except ImportError:
+    print('replace\t')
+    sys.exit(0)
 try:
     with open(os.environ['SPECKIT_MANIFEST']) as f:
         data = yaml.safe_load(f)

scripts/powershell/common.ps1

@@ -401,11 +401,16 @@ function Resolve-TemplateContent {
                 $strategy = 'replace'
                 $manifestFilePath = ''
                 $manifest = Join-Path $presetsDir "$presetId/preset.yml"
-                if (Test-Path $manifest) {
+                if ((Test-Path $manifest) -and (Get-Command python3 -ErrorAction SilentlyContinue)) {
                     try {
                         # Use python3 to parse YAML manifest for strategy and file path
                         $stratResult = & python3 -c @"
-import yaml, sys
+import sys
+try:
+    import yaml
+except ImportError:
+    print('replace\t')
+    sys.exit(0)
 try:
     with open(sys.argv[1]) as f:
         data = yaml.safe_load(f)

src/specify_cli/presets.py

@@ -637,7 +637,7 @@ def _reconcile_composed_commands(self, command_names: List[str]) -> None:
                 registered = False
                 for pack_id, _meta in PresetRegistry(self.presets_dir).list_by_priority():
                     pack_dir = self.presets_dir / pack_id
-                    if str(top_path).startswith(str(pack_dir)):
+                    if top_path.is_relative_to(pack_dir):
                         manifest_path = pack_dir / "preset.yml"
                         if manifest_path.exists():
                             try:
@@ -1170,7 +1170,19 @@ def install_from_directory(
                 "registered_skills": registered_skills,
             })
         except Exception:
-            # Roll back registry entry on failure
+            # 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)
+            if dest_dir.exists():
+                shutil.rmtree(dest_dir)
             self.registry.remove(manifest.id)
             raise
 
@@ -2276,8 +2288,16 @@ def resolve_content(
                 content = content + "\n\n" + layer_content
             elif strategy == "wrap":
                 if template_type == "script":
-                    content = layer_content.replace("$CORE_SCRIPT", content)
+                    placeholder = "$CORE_SCRIPT"
                 else:
-                    content = layer_content.replace("{CORE_TEMPLATE}", content)
+                    placeholder = "{CORE_TEMPLATE}"
+                if placeholder not in layer_content:
+                    raise PresetValidationError(
+                        f"Wrap strategy in '{layer['source']}' is missing "
+                        f"the {placeholder} placeholder. The wrapper must "
+                        f"contain {placeholder} to indicate where the "
+                        f"lower-priority content should be inserted."
+                    )
+                content = layer_content.replace(placeholder, content)
 
         return content