Refactor plugin registry into separate files per plugin

src/plugin_helper/planner.py

@@ -65,6 +65,26 @@ def _asset_matches_patterns(name: str, patterns: tuple[str, ...]) -> bool:
     return not patterns or any(fnmatch.fnmatch(name, pattern) for pattern in patterns)
 
 
+def _expand_required_dependencies(selected_ids: set[str], registry: Registry, lockfile: Lockfile) -> set[str]:
+    locked_ids = {plugin.id for plugin in lockfile.plugins}
+    expanded = set(selected_ids)
+    pending = list(selected_ids)
+    while pending:
+        plugin_id = pending.pop()
+        registry_plugin = registry.get(plugin_id)
+        if not registry_plugin:
+            continue
+        for dependency in registry_plugin.dependencies:
+            if not dependency.required:
+                continue
+            if dependency.id not in locked_ids:
+                raise ValueError(f"{plugin_id}: required dependency is not locked for this instance: {dependency.id}")
+            if dependency.id not in expanded:
+                expanded.add(dependency.id)
+                pending.append(dependency.id)
+    return expanded
+
+
 def create_plan(
     *,
     instance: str,
@@ -77,7 +97,11 @@ def create_plan(
     selected: set[str] | None = None,
     require_bootstrap: bool = True,
 ) -> tuple[dict[str, Any], Path]:
-    selected_ids = selected or {plugin.id for plugin in lockfile.plugins}
+    selected_ids = (
+        _expand_required_dependencies(selected, registry, lockfile)
+        if selected is not None
+        else {plugin.id for plugin in lockfile.plugins}
+    )
     changes: list[dict[str, Any]] = []
     warnings: list[str] = []