fix(#2748): pass browserProvider into skill() discovery

skill-context already filtered browser-related skills using the configured
browser provider, but the skill tool rebuilt discovery without forwarding
browserProvider. That caused skills like agent-browser to be prompt-visible
while skill() could still fail to resolve them unless browser_automation_engine.provider
was explicitly threaded through both paths.

Fix:
- pass skillContext.browserProvider from tool-registry into createSkillTool
- extend SkillLoadOptions with browserProvider
- forward browserProvider to getAllSkills()
- add regression tests for execution and description visibility

src/plugin/tool-registry.ts

@@ -113,6 +113,7 @@ export function createToolRegistry(args: {
     mcpManager: managers.skillMcpManager,
     getSessionID: getSessionIDForMcp,
     gitMasterConfig: pluginConfig.git_master,
+    browserProvider: skillContext.browserProvider,
     nativeSkills: "skills" in ctx ? (ctx as { skills: SkillLoadOptions["nativeSkills"] }).skills : undefined,
   })