fix(mcq): stop clipping Confirm question bodies

[ajlennon]

Summary

• Keep the Confirm decision-ask lead fully visible; scroll only the detail (command / To+body / meta).
• Remeasure wrapped Gtk labels after width settles (natural-height under-count was clipping the last line without a usable scrollbar).
• Raise the body height cap; mirror lead/detail on Windows.

Fixes Preloop Shell gates (and other tall Confirm cards) where Command: was cut off inside the pink card.

Hosts / platforms touched

• Cursor (Linux Gtk)
• Claude Code
• Claude Desktop / other stdio host
• Windows Phase 1 (tkinter text-only)
• Docs only (no behaviour change)

Test plan

Check	Result	Notes
uv run python scripts/test_match_transcript.py	Pass
uv run python scripts/test_doctor.py	Pass
uv run python scripts/test_acks.py	Pass
uv run python scripts/test_install.py	Pass
uv run python scripts/test_dialog_ergonomics.py	Pass	includes split_lead_detail + body-cap constants
uv run python scripts/test_windows_backend.py	Pass
uv run python scripts/test_contracts.py	Pass
uv run python scripts/test_mcq_images.py	Pass
check_setup in a real host	Skip
ask_multiple_choice dialog click	Pass	smoke open from fixed tree
Image preview in Gtk dialog (image/images)	Skip	unchanged
Keyboard 1–8 / Enter / Esc	Skip	unchanged
Freeform / Something else	Skip	unchanged
Speak / duck (if claiming voice)	Skip	text-only

Environment: Ubuntu, Cursor, DISPLAY=:0, text-only MCQ (ASK_QUESTION_AUDIO=0).

Behaviour contract

• No removal/rename of MCP tools without a migration note
• Cursor absolute-uv docs kept
• No lab IPs / home paths / secrets in tracked files
• If adding a host: N/A

AI assistance

• AI-assisted (Cursor) — verified unit ergonomics suite + dialog smoke open; human MCQ-approved create/merge