feat(telemetry): Add Sentry production monitoring and webhook alerts

[EKF0]

This PR implements P0-08: Add Production Monitoring & Alerts:

1. Sentry Next.js Integration: Configured client, server, and edge configs and integrated Sentry inside lib/telemetry.ts and next.config.ts.
2. Threshold Alerting & Spikes:
   • Bags API error rates sliding window (>= 3 errors / 429 or 5xx within 10 requests) triggers webhook alert with cooldown.
   • Immediate webhook alert on failed Solana pre-flight transaction simulations.
   • RPC latency warning alerts if confirmations exceed the limit (default 10,000ms).
3. Secure Webhook Routing: Secures webhook triggers from client-side bundles by creating a secure POST proxy route /api/telemetry/alert.
4. Environment Enhancements: Added validation rules and docs in lib/env.js and .env.example.
5. Testing: 100% covered with a new 7-test Vitest suite in test/telemetry.test.ts (all passing).

[vercel]

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[supabase]

This pull request has been ignored for the connected project zgqlbqmebjnsaxraqwmt because there are no changes detected in supabase directory. You can change this behaviour in Project Integrations Settings ↗︎.

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