feat(integrations): add n8n community node for Mem0

A programmatic n8n community node wrapping the hosted Mem0 v3 REST API:
add, search, get, get-many, update, delete, plus usableAsTool so the n8n
AI Agent can call it.

- Zero runtime dependencies (calls REST directly), TypeScript, ESLint clean —
  meets n8n verified-node requirements
- Add supports custom_instructions, custom_categories, includes, excludes,
  a client-side entity-id guard, and async event polling (itemIndex on errors)
- Anonymous opt-out telemetry (MEM0_TELEMETRY=false)
- Docs page + docs.json/llms.txt entry, ci-gate + release wiring, AGENTS.md rows
- Verified: tsc + ESLint + live E2E (add → search → get → delete) vs api.mem0.ai

Split out of #6057 per review (separate PRs per integration).

integrations/n8n-nodes-mem0/gulpfile.js

@@ -0,0 +1,16 @@
+const path = require('path');
+const { task, src, dest } = require('gulp');
+
+task('build:icons', copyIcons);
+
+function copyIcons() {
+	// Copy icons and the codex (*.node.json) next to the compiled nodes; tsc emits
+	// only .js, so these static assets need copying for n8n to pick them up.
+	const nodeSource = path.resolve('nodes', '**', '*.{png,svg,json}');
+	const nodeDestination = path.resolve('dist', 'nodes');
+	src(nodeSource).pipe(dest(nodeDestination));
+
+	const credSource = path.resolve('credentials', '**', '*.{png,svg}');
+	const credDestination = path.resolve('dist', 'credentials');
+	return src(credSource, { allowEmpty: true }).pipe(dest(credDestination));
+}