feat: publish standalone worker

Separate worker packaging and service lifecycle from the control plane.

internal/webapp/scan.go

@@ -0,0 +1,15 @@
+package webapp
+
+import "bufio"
+
+// bufioNewScanner is a thin wrapper around bufio.NewScanner with a
+// 1 MiB max line size. Most /proc files fit comfortably under that.
+// Splitting it out lets tests override the buffer size if needed.
+func bufioNewScanner(r interface {
+	Read(p []byte) (int, error)
+},
+) *bufio.Scanner {
+	s := bufio.NewScanner(r)
+	s.Buffer(make([]byte, 0, 64*1024), 1<<20)
+	return s
+}