canva-advanced-troubleshooting

# Canva Advanced Troubleshooting ## Overview Deep debugging for complex Canva Connect API issues — intermittent 5xx errors, stuck export jobs, OAuth token rotation failures, rate limit edge cases, and webhook delivery gaps. ## Systematic Layer Testing ```typescript interface LayerTest { layer: string; test: () => Promise<{ pass: boolean; details: string; durationMs: number }>; } async function diagnoseCanvaIssue(token: string): Promise<void> { const layers: LayerTest[] = [ { layer: 'DNS', test: async () => { const start = Date.now(); try { const { address } = await import('dns/promises').then(dns => dns.lookup('api.canva.com')); return { pass: true, details: `Resolved to ${address}`, durationMs: Date.now() - start }; } catch (e: any) { return { pass: false, details: e.message, durationMs: Date.now() - start }; } }, }, { layer: 'TLS', test: async () => { const start = Date.now(); try { const res = await fetch('https://api.canva.com/rest/v1/users/me', { method: 'HEAD', signal: AbortSignal.timeout(5000), }); return { pass: true, details: `TLS OK, HTTP ${res.status}`, durationMs: Date.now() - start }; } catch (e: any) { return { pass: false, details: e.message, durationMs: Date.now() - start }; } }, }, { layer: 'Auth', test: async () => { ...