feat(examples): rewrite baker-family as coherent Competition Week narrative

Rewrote the baker-family example around a unified story: the annual Harvest
Baking Competition is Saturday. Martha's sourdough starter Old Maggie is
sluggish from a cold snap, Jane is secretly entering the FreeStyle category,
Emma's science fair project is "The Chemistry of Fermentation", Henry is
judging for the first time and worried about impartiality, and Roland is
defending last year's title.

The week's schedules (Mon guild meeting → Tue test bakes → Wed sourcing →
Thu dough prep → Fri science fair → Sat competition → Sun recovery) are
now fully populated with narrative-specific actions.

Files split for composability:
- behaviors/baker_behaviors.sb → 5 focused files by character/domain
- schema/types.sb → 4 files (core, baking, world, social)
- schedules/work_schedules.sb → 4 files (one per schedule)
- relationships/baker_family_relationships.sb → family + bakery

Strong typing: replaced all enumerable string fields with concepts
(BakerSpecialty, Occupation, LocationType, InstitutionType, ParentingStyle,
Intensity, BakeryDomain, BakingDiscipline, ManagementDomain,
CompetitiveAdvantage).

Remove new-syntax-demo.sb (superseded by baker-family example).

examples/baker-family/characters/henry.sb

@@ -18,12 +18,21 @@ character Henry from Person {
     ---backstory
     Henry taught history at the local school for over forty years before
     retiring. He has been a daily customer at the bakery since Martha
-    first opened its doors. Every morning at precisely seven o'clock,
-    he arrives for a sourdough loaf and a chat.
+    first opened its doors — every morning at seven o'clock, a sourdough
+    loaf and a chat. The bakery is his anchor to the community.
 
-    He watched Emma grow up and occasionally helps her with her homework
-    when he stops by. The bakery is his anchor to the community now that
-    he no longer teaches. Martha always sets aside his favorite loaf,
-    and Jane saves him a croissant on Saturdays.
+    This year, the Bakers Guild invited him to sit on the judging panel
+    for the Harvest Baking Competition. It is the first time he has been
+    a judge rather than a spectator, and he is quietly terrified. He
+    knows the competition's two-hundred-year history better than anyone
+    — he wrote a monograph on it during his teaching days — but judging
+    Martha's bread fairly when she saves him his favorite loaf every
+    morning feels like a conflict of interest.
+
+    He has been re-reading the guild's judging criteria and practicing
+    his palate with different breads from the market. He does not want
+    to let anyone down — not Martha, not Roland, not the guild. Emma
+    asked him to come to her science fair on Friday, and he would not
+    miss it for the world.
     ---
 }