fix(integrations): address code-review findings

n8n: throw on FAILED memory events (was silently returned), poll on any
non-terminal status (PENDING or RUNNING), use top_k (not limit) for
search, coerce search/getAll responses to arrays, guard invalid-JSON
metadata, reject empty updates, mark user_id required; lint clean.

Zapier: coerce boolean fields (String(x) !== 'false') + boolean defaults
so "Wait"/"Infer = No" are honored, throw on HTTP >= 400 (was silent
empty/fake-success), throw on FAILED events, use top_k, numeric coercion
with clamping, mark user_id required.

integrations/zapier-mem0/authentication.js

@@ -27,5 +27,5 @@ module.exports = {
 		},
 	],
 	// Shown on the connection label in the Zap editor.
-	connectionLabel: 'Mem0 ({{bundle.authData.baseUrl}})',
+	connectionLabel: 'Mem0',
 };