Reject coerced and out-of-range skip_on_away values

Review remediation for PR #194:
- Admin create/edit request models use StrictBool so JSON 0/1 and
  "true"/"false" are 422 instead of being coerced to a bool.
- Fresh-schema quest_definitions gains CHECK (skip_on_away IN (0, 1));
  migrated databases (column added without the CHECK) are guarded by a
  DAO validator applied at every write path that takes the flag.
- QuestDefinitionsDao.update() accepts skip_on_away (None leaves it
  unchanged), validated like the other write paths.

Task: ded75ab8-0219-4d52-aefa-82c09e0b5e6b

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

custom_components/nestquest/core/schema.py

@@ -258,7 +258,7 @@ QUEST_DEFINITIONS_TABLE_SQL = """(
     due_time TEXT,
     is_active INTEGER NOT NULL DEFAULT 1 CHECK (typeof(is_active) = 'integer' AND is_active IN (0, 1)),
     created_at TEXT NOT NULL,
-    skip_on_away INTEGER NOT NULL DEFAULT 1
+    skip_on_away INTEGER NOT NULL DEFAULT 1 CHECK (skip_on_away IN (0, 1))
 )"""
 
 SCHEMA_V1_QUEST_DEFINITIONS_DDL: list[str] = [