chore(build): bump Go toolchain to 1.27.0

Go 1.27.0 shipped on 2026-08-19. Raise the go directive and the builder
image so Docker and release builds pick it up; every CI job already reads
the version from go.mod, and golangci-lint v2.13.1 release binaries are
themselves built with go1.27.0, so the lint job needs no pin change.

internal/xray/geodata/query.go

@@ -103,10 +103,7 @@ func sliceBounds(total, offset, limit int) (int, int) {
 	if limit <= 0 || limit > MaxPageSize {
 		limit = MaxPageSize
 	}
-	to := offset + limit
-	if to > total {
-		to = total
-	}
+	to := min(offset+limit, total)
 	return offset, to
 }