MVP: no legacy code

Decision

AskCal is an MVP. Prefer a clean refactor to a patch, keep no legacy support, and delete unused code, files and notes.

Why

Set by the owner on 2026-09-27. There are no old app versions in users' hands that need a migration path, so keeping old code paths only adds cost.

Impact

• No compatibility shims, no "old way still works" branches.
• Unused functions, files and .md notes are deleted, not kept "for later".
• Revisit this decision once paying users are on a version that a change could break.