feat(train): the body's figures in a sealed, synced profile (ADR 0030, D33, D34)

A person's profile, one row per person (its ID derived from theirs),
sealed like a workout: sex, birth date, height, weight, resting and
maximum heart rate, VO2max, training background, typical day and sleep
goal, each optional. "Your body" in the account sheet edits it; the
Loop's setup is to reuse its form. The migration only adds the synced
table `profile`, deleted with the person's sync space.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

apps/train/halkyon_train_server/migrations/migration_registry.txt

@@ -6,3 +6,4 @@
 
 20261028075229917-initial
 20261028101012641-workouts
+20261028164640000-profile