Rewrite plugin installer as a declarative manifest/engine framework for reliable mix-and-match plugin installs, with backup/restore support and assorted plugin fixes (Hardcover file API, Bookerly/Hardcover SettingAction registration, GitHubSync include path, Lockscreen render timing)

framework/discovery.py

@@ -0,0 +1,38 @@
+import importlib.util
+import os
+
+from .engine import SelectedPlugin
+
+
+def discover_all(plugins_dir):
+    """Return {name: (plugin_dir, get_manifest_callable)} for every plugin
+    directory that has a plugin.py exposing get_manifest(ctx)."""
+    found = {}
+    for name in sorted(os.listdir(plugins_dir)):
+        plugin_dir = os.path.join(plugins_dir, name)
+        manifest_path = os.path.join(plugin_dir, "plugin.py")
+        if not os.path.isdir(plugin_dir) or not os.path.exists(manifest_path):
+            continue
+        spec = importlib.util.spec_from_file_location(f"xteink_plugin_{name}", manifest_path)
+        module = importlib.util.module_from_spec(spec)
+        spec.loader.exec_module(module)
+        if not hasattr(module, "get_manifest"):
+            continue
+        found[name] = (plugin_dir, module.get_manifest)
+    return found
+
+
+def build_selected(names, plugins_dir, ctx):
+    """Build a deterministic, sorted-by-name list of SelectedPlugin for the
+    given plugin names. Order doesn't affect correctness (the engine derives
+    shared files from the whole set at once) but keeping it stable makes
+    output/diffs reproducible."""
+    found = discover_all(plugins_dir)
+    selected = []
+    for name in sorted(names):
+        if name not in found:
+            raise KeyError(f"Unknown plugin: {name} (available: {', '.join(sorted(found))})")
+        plugin_dir, get_manifest = found[name]
+        manifest = get_manifest(ctx)
+        selected.append(SelectedPlugin(name=name, plugin_dir=plugin_dir, manifest=manifest))
+    return selected