docs(lab1): add QuickTicket failure analysis

[m1d0rfeed]

Lab 1 submission

I deployed the QuickTicket system, verified the normal request flow, and tested how the application behaves when individual dependencies fail.

Completed:

• Task 1 - deployed QuickTicket and completed failure exploration
• Task 2 - implemented graceful degradation for unavailable payments
• Task 3 - completed GitHub community engagement
• Bonus Task - measured resource usage under normal load and fault injection

What I tested

I verified the normal event -> reserve -> pay flow and then stopped the following components one by one:

• payments
• events
• redis
• postgres

I documented the HTTP responses, health status, and user impact for each failure scenario.

For Task 2, I updated the gateway so that payment connection errors and timeouts return a clear HTTP 503 response while reservations remain available.

I also ran the load generator under normal conditions, during a payments outage, and with payment failure injection enabled.