fix: bug fixes, test coverage, and CI workflow

- Fix Nodes.First() panic on empty slice (return nil)
- Fix ticker leak in archive.go (create once, defer Stop)
- Fix cookie path matching for empty and root paths
- Fix lost query params in google.go (u.Query().Set was discarded)
- Fix type assertion panic in useragents.go
- Fix dropped date parse error in powerball.go
- Remove unreachable dead code in megamillions.go and powerball.go
- Simplify document.go WaitForNetworkIdle, remove unused root field
- Remove debug fmt.Println calls across codebase
- Replace panic(err) with stderr+exit in all cmd/ programs
- Fix duckduckgo cmd: remove useless defer, return error on bad safesearch
- Fix archive cmd: ToConfig returns error instead of panicking
- Add 39+ unit tests across 6 new test files
- Add Gitea Actions CI workflow (build, test, vet in parallel)

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

sites/duckduckgo/cmd/duckduckgo/main.go

@@ -26,7 +26,7 @@ var Flags = DuckDuckGoFlags{
 	},
 }
 
-func (f DuckDuckGoFlags) ToConfig(cmd *cli.Command) duckduckgo.Config {
+func (f DuckDuckGoFlags) ToConfig(cmd *cli.Command) (duckduckgo.Config, error) {
 	var res = duckduckgo.DefaultConfig
 
 	if r := cmd.String("region"); r != "" {
@@ -42,11 +42,11 @@ func (f DuckDuckGoFlags) ToConfig(cmd *cli.Command) duckduckgo.Config {
 		case "off":
 			res.SafeSearch = duckduckgo.SafeSearchOff
 		default:
-			panic("invalid safe search value")
+			return res, fmt.Errorf("invalid safe search value: %s", s)
 		}
 	}
 
-	return res
+	return res, nil
 }
 
 func deferClose(cl io.Closer) {
@@ -66,8 +66,10 @@ func main() {
 		Usage: "Search DuckDuckGo",
 		Flags: flags,
 		Action: func(ctx context.Context, command *cli.Command) error {
-			c := Flags.ToConfig(command)
-			defer deferClose(nil)
+			c, err := Flags.ToConfig(command)
+			if err != nil {
+				return err
+			}
 
 			query := strings.TrimSpace(strings.Join(command.Args().Slice(), " "))
 
@@ -105,9 +107,8 @@ func main() {
 		},
 	}
 
-	err := cli.Run(context.Background(), os.Args)
-
-	if err != nil {
-		panic(err)
+	if err := cli.Run(context.Background(), os.Args); err != nil {
+		fmt.Fprintf(os.Stderr, "error: %v\n", err)
+		os.Exit(1)
 	}
 }