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Remove new-syntax-demo.sb (superseded by baker-family example).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

@@ -12,7 +12,7 @@ character Roland from Baker {
     age: 42
 
     // Baker-specific traits
-    specialty: "rye bread"
+    specialty: RyeBread
     baking_skill: 0.75
     customer_relations: 0.60
     skill_tier: Journeyman
@@ -23,18 +23,25 @@ character Roland from Baker {
 
     // Work ethic
     work_ethic: 0.80
-    occupation: "baker"
+    occupation: Baker
 
     ---backstory
     Roland runs a bakery in the neighboring town. He learned baking from
     his father and considers himself the rightful best baker in the region.
-    His rye bread is excellent, but he lacks Martha's warmth with customers
-    and Jane's artistic flair.
+    Last year, he won the Harvest Baking Competition with a dark rye that
+    the judges called "revelatory" — the first time in three years that
+    Martha did not take the title. He intends to defend his championship.
 
-    He sees Martha's bakery as his chief competition and often tries to
-    undercut her prices at the market. Despite the rivalry, there is a
-    grudging respect between them. Roland once admitted, after too much
-    ale at the harvest festival, that Martha's sourdough was better than
-    his own.
+    He has been experimenting with a new fermented rye technique, using a
+    wild starter he cultivated from grain husks foraged in the hills. The
+    results are promising but inconsistent, and he has been running test
+    bakes every other evening. He hired Thomas, Martha's former apprentice,
+    last spring — a move that was practical (he needed the help) but that
+    Martha took as a personal betrayal.
+
+    Roland respects Martha's skill more than he would ever admit. After
+    too much ale at last year's harvest festival, he told Henry that
+    Martha's sourdough was better than his own. He regretted saying it
+    immediately, and has been trying to prove himself wrong ever since.
     ---
 }