fix(routines): test the copy, name what Yes agrees to, and true up the docs

Make it mine's copying was inline in App and untested; it is now a pure
function with a test, so a change to either store can't make the copy
silently arrive empty. The question's buttons now say what they answer
when heard out of context. The prefs block and the spec now match what
shipped.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/DATA-MODEL.md

@@ -222,7 +222,11 @@ Namespaced, versioned, and small. Nothing here ever goes to the server.
                                 //   timelineDayWidth, timelineGroup, showUpcoming,
                                 //   timelineSplitUpcoming, detectDaily, showChores,
                                 //   showCompleted, showIgnored, theme, regionConfirmed,
-                                //   onboarded }
+                                //   onboarded, routineGames?, routinesAsked? }
+                                // routineGames is the games whose built-in weekly tasks
+                                // the reader turned on; routinesAsked the games already
+                                // asked about. Both absent means none — built-ins are
+                                // opt-in for every install. PRD F17.
                                 // timelineDayWidth is px per day on the board, stored as the
                                 // measurement rather than a step number and read through
                                 // snapDayWidth — so a value from an older ladder still opens