Default output is CSV, not markdown — violates contract

[DTTerastar]

Severity

major

Summary

The shipped binary's default output for every export subcommand is CSV, but the quantcli contract (and this CLI's own prime text) says markdown is the default and --format csv is opt-in.

Reproduce

$ withings-export activity --since 1d
date,timezone,steps,distance_m,...   <-- CSV header
2026-04-25,America/New_York,456,...

$ withings-export sleep --since 7d --derive
date,start,end,timezone,...           <-- CSV header

$ withings-export workouts --since 7d
date,start,end,category,...           <-- CSV header

$ withings-export measurements --since 30d
date,type,type_code,value,...         <-- CSV header

Help text confirms the inverted contract:

$ withings-export activity --help
  ...
  --json   Output as JSON instead of CSV   <-- says CSV is the default

Expected

Per https://github.com/quantcli/common/blob/main/CONTRACT.md (and this CLI's prime long help): default = markdown, --format csv and --format json are opt-ins.

This is fixed on main (PR #7) but missing from the released binary — see #14.

[DTTerastar]

Does not reproduce against HEAD b580683: /tmp/qa-bin/withings-export activity --since 1d now emits markdown ("Activity 2026-04-25 ...") and activity --help shows --format string ... (default "markdown"). Fixed by PR #7. Closing.