docs(post-release): align README, server.json, package wrappers with v0.6.1

- README badges: languages 66->155, agents 10->11, tests 2586->2812 (actual count from v0.6.1 test run)
- README: VirusTotal table, primary VT badge link, all '66 languages' references, expanded language list with all newly added grammars
- server.json: bump 0.5.5->0.6.1 (was two releases behind), update all download URLs and sha256s
- pkg/scoop, homebrew, aur, chocolatey, winget: bump to 0.6.1 with new sha256s from v0.6.1 checksums.txt
- pkg/winget: new 0.6.1/ manifest directory (winget keeps version history; 0.6.0/ retained)
- pkg/npm/README: language and agent counts