fix: stop client from repeatedly calling endpoint

[Oxiang]

Problem

To stop runaway API calls to /api/stats in development environment on fresh install

Reasons:

1. server returns wrong values
2. client having unlimited retries

Steps involved:

1. opening homepage
2. in StatisticsSilver.jsx > useEffect runs on mount
3. loadStats() was called
4. checks for any NULL values in userCount, linkCount and clickCount.
5. confirmed that all values are NULL > call /api/stats endpoint
6. received userCount = 0, linkCount = 0 and clickCount = NULL
7. apply changes and re-renders
8. re-rendering triggers useEffect
9. loadstats() called again
10. checks that confirmed that clickCount is NULL > call /api/stats/ endpoint
11. repeat step 6

#659

Solution

To address both the client side and server side issues.

For the client side, we will prevent it from calling the endpoint multiple times.

• useEffect in StatisticSilver.js will only be called once on mount.

For the server side, we will ensure clickCount returns 0 instead of NaN.

• The function, getGlobalStatistics, in StatisticsRepository.ts will return 0 for clickCount instead of NaN

[LoneRifle]

lgtm