Address the Copilot review on #26.
#1 The game_start / art_style_select payload fields were typed as bare
`string`, so free text could still slip through despite the "content-free
by construction" claim. Add lib/options.ts as the single source of truth
for the selector option sets (`as const` → literal-union types), have the
home OPTS render from those arrays, and type the analytics fields from the
derived unions (gender/art_style/plot_style/pacing/style) plus a template
type for `card`. Free text now fails to compile; no casts at call sites.
#2 The /play heartbeat scheduled its 30s interval unconditionally. Gate the
effect on the same NEXT_PUBLIC_UMAMI_* env used for script injection, so
nothing is scheduled when the tracker is off (visibility check kept — a
hidden tab still never emits).
#3 choice_select no longer emits a -1 choice_index: skip the event when the
index can't be resolved instead of polluting the index distribution.
Verified with tsc (exit 0) and a throwaway negative test: free text in any
of the six fields raises TS2322, valid enum/template values compile.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
yuanzonghao
e095650944