feat(amp): add root-level /threads routes for CLI compatibility

internal/api/modules/amp/routes.go

@@ -128,6 +128,7 @@ func (m *AmpModule) registerManagementRoutes(engine *gin.Engine, baseHandler *ha
 	// Root-level routes that AMP CLI expects without /api prefix
 	// These need the same security middleware as the /api/* routes (dynamic for hot-reload)
 	rootMiddleware := []gin.HandlerFunc{noCORSMiddleware(), m.localhostOnlyMiddleware()}
+	engine.GET("/threads/*path", append(rootMiddleware, proxyHandler)...)
 	engine.GET("/threads.rss", append(rootMiddleware, proxyHandler)...)
 
 	// Root-level auth routes for CLI login flow

internal/api/modules/amp/routes_test.go

@@ -47,6 +47,7 @@ func TestRegisterManagementRoutes(t *testing.T) {
 		{"/api/meta", http.MethodGet},
 		{"/api/telemetry", http.MethodGet},
 		{"/api/threads", http.MethodGet},
+		{"/threads/", http.MethodGet},
 		{"/threads.rss", http.MethodGet}, // Root-level route (no /api prefix)
 		{"/api/otel", http.MethodGet},
 		{"/api/tab", http.MethodGet},