[Feature] /context: collapse MCP tools to one line per server (opt-in --verbose for full list)

What

/context lists every individual MCP tool by name. With only a couple of servers connected the MCP section already dominates the output: chrome-devtools alone is ~29 tool lines, XcodeBuildMCP ~25, plus any account connectors (Gmail/Calendar/Drive/Notion). The result is dozens of lines that scroll the actually-useful summary (token breakdown, free space) off screen.

Note these tools are shown as "loaded on-demand" (deferred), so this is about readability of /context, not token cost. The information is fine; the default verbosity is the problem.

Request

Collapse the MCP section to one line per server with a tool count by default, e.g.:

MCP tools · /mcp (loaded on-demand)
├ chrome-devtools     29 tools
├ XcodeBuildMCP       25 tools
├ tavily               5 tools
└ claude_ai_Gmail      2 tools

…and expose the full per-tool list behind an opt-in, e.g. /context --verbose (or /context mcp <server> to expand a single server).

Why

• A user with 3–4 servers sees 60+ tool lines they did not ask for every time they run /context.
• The per-server rollup is what people actually want to reason about ("which servers are connected, how heavy is each").
• Deferred tools especially: the names carry little signal, so listing all of them by default is mostly noise.

Nice to have

• Show each server's token contribution next to the count (the deferred-index cost), so users can see which server is heaviest at a glance.

Environment

• Claude Code v2.1.178
• macOS (darwin)