fix(openclaw): emit empty configSchema in plugin manifests

OpenClaw rejects generated plugin manifests that omit configSchema, even for tool plugins with no user configuration. Always emit an empty object schema so converted installs boot cleanly.\n\nAdd converter and writer regression coverage for the manifest shape.\n\nFixes #224

src/converters/claude-to-openclaw.ts

@@ -64,6 +64,10 @@ function buildManifest(plugin: ClaudePlugin, skillDirs: string[]): OpenClawPlugi
     id: plugin.manifest.name,
     name: formatDisplayName(plugin.manifest.name),
     kind: "tool",
+    configSchema: {
+      type: "object",
+      properties: {},
+    },
     skills: skillDirs.map((dir) => `skills/${dir}`),
   }
 }

src/types/openclaw.ts

@@ -2,16 +2,18 @@ export type OpenClawPluginManifest = {
   id: string
   name: string
   kind: "tool"
-  configSchema?: {
-    type: "object"
-    additionalProperties: boolean
-    properties: Record<string, OpenClawConfigProperty>
-    required?: string[]
-  }
+  configSchema: OpenClawConfigSchema
   uiHints?: Record<string, OpenClawUiHint>
   skills?: string[]
 }
 
+export type OpenClawConfigSchema = {
+  type: "object"
+  properties: Record<string, OpenClawConfigProperty>
+  additionalProperties?: boolean
+  required?: string[]
+}
+
 export type OpenClawConfigProperty = {
   type: string
   description?: string