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/tools/skill/tools.test.ts

@@ -583,6 +583,38 @@ describe("skill tool - dynamic description cache invalidation", () => {
 
 
 
+describe("skill tool - browserProvider forwarding", () => {
+  it("passes browserProvider to getAllSkills during execution", async () => {
+    // given: a skill tool configured with agent-browser as browserProvider
+    // and a pre-provided agent-browser skill (simulating what skill-context provides)
+    const agentBrowserSkill = createMockSkill("agent-browser")
+    const tool = createSkillTool({
+      skills: [agentBrowserSkill],
+      browserProvider: "agent-browser",
+    })
+
+    // when: executing skill("agent-browser")
+    const result = await tool.execute({ name: "agent-browser" }, mockContext)
+
+    // then: skill should resolve successfully (not filtered out)
+    expect(result).toContain("Skill: agent-browser")
+  })
+
+  it("description includes agent-browser when browserProvider is agent-browser", () => {
+    // given
+    const agentBrowserSkill = createMockSkill("agent-browser")
+
+    // when
+    const tool = createSkillTool({
+      skills: [agentBrowserSkill],
+      browserProvider: "agent-browser",
+    })
+
+    // then
+    expect(tool.description).toContain("agent-browser")
+  })
+})
+
 describe("skill tool - nativeSkills integration", () => {
   it("merges native skills exposed by PluginInput.skills.all()", async () => {
     //#given