docs(recipes): document isRecipe-flag behavior in get_recipe_box (v0.11.8)

Documentation-only release explaining the isRecipe flag:
- isRecipe='true': Real recipes in the recipe box
- isRecipe='false': Free-text stubs from meal planner OR old imported recipes
  never properly tagged (e.g. recipe/16282169_7055369 'Elsässer Flammkuchen')

get_recipe_box filters strictly on isRecipe='true' — consistent with Family Wall app.

Updated SPEC.md, README.md, CLAUDE.md with v0.11.8.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "mcp-familywall"
-version = "0.11.7"
+version = "0.11.8"
 description = "MCP server for Family Wall — read your family's lists and tasks via Claude"
 readme = "README.md"
 requires-python = ">=3.12"