added demo of coordinates conversion using Amap service

[BisonLeo]

feat(webui): add SRT upload and locus polygon support
fix(map): ensure map is initialized after AMap script loads, and separated api key loading
chore: update .gitignore to exclude map-key.js

To try, you need to register an Amap account for API key and put it in map-key.js
then run with
npm run webui

Then use browser to access http://localhost:3000

[BisonLeo]

To test the rendering of polygon in Amap using converted coordinates, use the SRT subtitle file to try
DJI_0674.zip
which is from DJI drone saved format as below.

Actually, any text file with proper format of regex will be processed.

/\[latitude: ([^\]]+)\] \[longitude: ([^\]]+)\] \[altitude: ([^\]]+)\]/g;

[latitude: 29.552354] [longitude: 121.587414] [altitude: 16.500000]

1
00:00:00,000 --> 00:00:00,033
<font size="36">SrtCnt : 1, DiffTime : 33ms
2025-06-15 10:16:10,657,571
[iso : 100] [shutter : 1/640.0] [fnum : 280] [ev : 0] [ct : 5094] [color_md : default] [focal_len : 224] [dzoom_ratio: 10000, delta:0],[latitude: 29.552354] [longitude: 121.587414] [altitude: 16.500000] 
</font>

2
00:00:00,033 --> 00:00:00,066
<font size="36">SrtCnt : 2, DiffTime : 33ms
2025-06-15 10:16:10,690,944
[iso : 100] [shutter : 1/640.0] [fnum : 280] [ev : 0] [ct : 5095] [color_md : default] [focal_len : 224] [dzoom_ratio: 10000, delta:0],[latitude: 29.552354] [longitude: 121.587414] [altitude: 16.500000] 
</font>