feat: implement dynamic changelog loading from API

- Add GET /api/changelog endpoint to fetch changelog from CHANGELOG.md
- Create service/changelog.go to parse CHANGELOG.md markdown file
- Add handler/changelog.go to handle changelog requests
- Update ChangelogDrawer component to fetch from API instead of hardcoded data
- Export apiFetch from lib/api.ts for public use
- Add changelog parser tests with 14 version entries verified

server/go.mod

@@ -5,6 +5,7 @@ go 1.24.0
 require (
 	github.com/gin-gonic/gin v1.9.1
 	github.com/golang-jwt/jwt/v5 v5.3.0
+	github.com/xuri/excelize/v2 v2.10.1
 	github.com/yeka/zip v0.0.0-20231116150916-03d6312748a9
 	go.mongodb.org/mongo-driver v1.13.1
 	golang.org/x/text v0.34.0
@@ -39,7 +40,6 @@ require (
 	github.com/xdg-go/scram v1.1.2 // indirect
 	github.com/xdg-go/stringprep v1.0.4 // indirect
 	github.com/xuri/efp v0.0.1 // indirect
-	github.com/xuri/excelize/v2 v2.10.1 // indirect
 	github.com/xuri/nfp v0.0.2-0.20250530014748-2ddeb826f9a9 // indirect
 	github.com/youmark/pkcs8 v0.0.0-20181117223130-1be2e3e5546d // indirect
 	golang.org/x/arch v0.3.0 // indirect