Add unique CodeQL repo count to count command when --codeql flag is used

[Copilot]

Summary

When using the --codeql flag with the count command, the output now additionally includes the number of unique repositories that contain at least one CodeQL-supported language. The existing per-language repo counts continue to be displayed across all three subcommands (count, trend, data).

Changes

cmd/common.go

• Added GetCodeQLLanguages() helper function to return the set of CodeQL-supported languages, avoiding duplication of the hardcoded language map
• Refactored IsCodeQLLanguage() to use the new helper
• Added HasCodeQLLanguage() function that checks if a repository's languages contain at least one CodeQL-supported language

cmd/count.go

• Added a codeqlRepos counter that tracks the number of unique repositories with at least one CodeQL-supported language during enumeration
• After the language table is rendered, prints the unique repo count when --codeql is set

README.md

• Updated documentation to describe the new output when using --codeql with the count command

Security Summary

No security vulnerabilities were introduced or discovered. CodeQL analysis returned 0 alerts.

Release Type

• Major - Breaking changes
• Minor - New features, backwards compatible
• Patch - Bug fixes, backwards compatible