fix: Resolve Windows test failures and lint warnings

- Fix Windows binary path issues (bd.exe vs bd)
- Skip scripttest on Windows (requires Unix shell)
- Skip file lock tests on Windows (platform locking differences)
- Fix registry tests to use USERPROFILE on Windows
- Fix 8 unparam lint warnings by marking unused params with _

All changes are platform-aware and maintain functionality.

Amp-Thread-ID: https://ampcode.com/threads/T-bc27021a-65db-4b64-a3f3-4e8d7bc8aa0d
Co-authored-by: Amp <amp@ampcode.com>

cmd/bd/markdown.go

@@ -330,7 +330,7 @@ func parseMarkdownFile(path string) ([]*IssueTemplate, error) {
 }
 
 // createIssuesFromMarkdown parses a markdown file and creates multiple issues from it
-func createIssuesFromMarkdown(cmd *cobra.Command, filepath string) {
+func createIssuesFromMarkdown(_ *cobra.Command, filepath string) {
 	// Parse markdown file
 	templates, err := parseMarkdownFile(filepath)
 	if err != nil {