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>

interactive.go

@@ -227,13 +227,12 @@ func NewInteractiveBrowser(ctx context.Context, opts ...PlayWrightBrowserOptions
 }
 
 func (ib *interactiveBrowser) Navigate(url string) (string, error) {
-	resp, err := ib.page.Goto(url, playwright.PageGotoOptions{
+	_, err := ib.page.Goto(url, playwright.PageGotoOptions{
 		WaitUntil: playwright.WaitUntilStateLoad,
 	})
 	if err != nil {
 		return "", fmt.Errorf("navigation failed: %w", err)
 	}
-	_ = resp
 	return ib.page.URL(), nil
 }