Squash MCP tools into one CLI-style tool per entity

[DenysKuchma]

Summary

#48

94 per-operation tools replaced with 17 CLI-style tools — one per entity.

Operations are passed as the required command argument:
{ "name": "tests", "arguments": { "command": "list", "tql": "priority == 'high'" } }

• Migration: <entity>_<op> → <entity> + "command": "<op>" (incl. tests_share → tests/share, tests_issues_link → tests/issues_link)
• New functionality = new command, the tool list doesn't grow
• Registry/API-client logic unchanged; dispatch is <entity>_<command> → existing op handler
• Profiles: core drops rare entity tools, read restricts the command enum to read-only
• Also fixes found by live testing on beta: attachment upload multipart field (file → files) and unregistered tags_search