feat(export): add activity description fetch/export with rate-limit retry

[rarepops]

• fetch per-activity descriptions and include them in the Excel export
• add Years selector and Refresh button to the export page
• add dev-only Clear cache button to force a full re-fetch
• stop retrying on Strava HTTP 429 and add a cooldown + Retry button

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[entorb]

Dear @rarepops , thank you very much for this PR! I will try to review and test it in the next days.

[entorb]

Excellent work!!!

I am just a bit concerned about hitting the API rate limit and hence blocking other users. Current limits are

Overall Rate Limits 3,300 requests every 15 minutes, 165,000 daily
Read Rate Limits 600 requests every 15 minutes, 30,000 daily
Number of athletes allowed to connect 9,999
Number of athletes currently connected 2,654

I see 2 ways:

1. contact Strava (again) to ask to include the description in the activity list api
2. request higher limits via https://developers.strava.com/docs/rate-limits/

[rarepops]

Yeah I needed the comments and thought it was easier to do it myself. But yes you are right about the API rate limits... that's just how Strava works i guess... and I doubt them including the description in the activity list will happen soon or at all.

It is a bit frustrating, but i think the way i made it is pretty ok given the constraints. I guess the biggest issue might be where it's stored, because for local development you have local storage and you store them in the folder. But if it's running in production, i guess the server needs to keep the cache around for a bit... I don't know that part and will leave it up to you to potentially handle it