Expand test coverage across server, agent, and web; fix bugs found during audit.

Adds hundreds of unit/integration/e2e tests, fixes WS bcrypt auth, config merge, fleet analytics, agent schedule/log tail, and documents stale PROBLEMS items. Updates PROBLEMS.md, README, and test scripts; ignores local spread-kits and coverage dirs.

agent/deploy/hollow_test.go

@@ -0,0 +1,18 @@
+package deploy
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestRunHollowedUnavailableWithoutTag(t *testing.T) {
+	err := RunHollowed("C:\\Windows\\System32\\notepad.exe", []byte{0})
+	if err == nil {
+		t.Fatal("expected error on default build")
+	}
+	msg := err.Error()
+	if !strings.Contains(msg, "hollowing") && !strings.Contains(msg, "not available") {
+		t.Fatalf("unexpected error: %q", msg)
+	}
+}
+