v0.3.0: fix HTTP client leak, add tests and CI pipeline

Reuse a single long-poll HTTP client instead of creating one per
Events() call (~every 30s). Make TLS skip-verify configurable via
syncthing_insecure_tls. Log previously swallowed config errors.
Add unit tests for all monitor trackers, config, and state logic.
Add CI workflow (vet, golangci-lint, govulncheck, go test -race).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

internal/monitor/state_test.go

@@ -0,0 +1,68 @@
+package monitor
+
+import (
+	"testing"
+
+	"git.davoryn.de/calic/syncwarden/internal/icons"
+)
+
+func TestStateFromFolders_Empty(t *testing.T) {
+	got := stateFromFolders(nil, false)
+	if got != icons.StateIdle {
+		t.Errorf("empty folders should be idle, got %d", got)
+	}
+}
+
+func TestStateFromFolders_Idle(t *testing.T) {
+	folders := []FolderInfo{
+		{ID: "a", State: "idle"},
+		{ID: "b", State: "idle"},
+	}
+	got := stateFromFolders(folders, false)
+	if got != icons.StateIdle {
+		t.Errorf("all idle should be StateIdle, got %d", got)
+	}
+}
+
+func TestStateFromFolders_Syncing(t *testing.T) {
+	folders := []FolderInfo{
+		{ID: "a", State: "idle"},
+		{ID: "b", State: "syncing"},
+	}
+	got := stateFromFolders(folders, false)
+	if got != icons.StateSyncing {
+		t.Errorf("syncing folder should produce StateSyncing, got %d", got)
+	}
+}
+
+func TestStateFromFolders_ScanningIsSyncing(t *testing.T) {
+	folders := []FolderInfo{
+		{ID: "a", State: "scanning"},
+	}
+	got := stateFromFolders(folders, false)
+	if got != icons.StateSyncing {
+		t.Errorf("scanning should map to StateSyncing, got %d", got)
+	}
+}
+
+func TestStateFromFolders_ErrorOverSyncing(t *testing.T) {
+	folders := []FolderInfo{
+		{ID: "a", State: "syncing"},
+		{ID: "b", State: "error"},
+	}
+	got := stateFromFolders(folders, false)
+	if got != icons.StateError {
+		t.Errorf("error should take priority over syncing, got %d", got)
+	}
+}
+
+func TestStateFromFolders_PausedOverAll(t *testing.T) {
+	folders := []FolderInfo{
+		{ID: "a", State: "error"},
+		{ID: "b", State: "syncing"},
+	}
+	got := stateFromFolders(folders, true)
+	if got != icons.StatePaused {
+		t.Errorf("paused should override all states, got %d", got)
+	}
+}