fix(mcp-panel): sanitize multiline text and make Keep & Close apply changes

[gpmarques]

What

This PR applies a minimal, targeted fix to mcp-panel.ts for two UX/rendering issues in the /mcp TUI panel.

Changes included

1. Sanitize display text

   • Added sanitizeDisplayText(...) to normalize external metadata used in rendering.
   • Strips ANSI escape sequences and control characters.
   • Collapses newlines/tabs/whitespace into single-line display text.

2. Keep discard behavior

   • In discard confirmation, selecting Keep on Enter now closes the panel and applies changes (done(buildResult())) instead of only leaving confirmation mode.

3. Clarify button label

   • Renamed confirmation button from Keep to Keep & Close to match behavior.

4. Protect row rendering from multiline content

   • Updated row(...) to force one-line content before truncation, preventing box/layout corruption from multiline/control characters.

5. Use sanitized values in server/tool rows

   • renderServerRow(...): sanitize server.name and server.importKind.
   • renderToolRow(...): sanitize tool.name and tool.description.
   • Width/truncation now use sanitized text, improving stable alignment.

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Why

Two user-facing issues were reproducible in the current panel behavior:

1. Layout breaks with multiline tool descriptions

   • Some MCP metadata (e.g., descriptions with line breaks/args blocks or control chars) can spill across lines and break bordered row rendering.
   • Sanitizing + enforcing single-line row rendering makes the TUI robust against untrusted/irregular metadata.

2. “Keep” in discard confirm is misleading

   • Previously, Keep only closed the confirmation prompt, not the panel, which is unexpected and easy to misinterpret.
   • Updating the action to “keep changes and close” plus renaming to Keep & Close aligns behavior with user expectation and label semantics.