Adds _MEAL_SIGNALS table to tag_inferrer with title-only matching for:
meal:Breakfast — pancakes, waffles, frittata, oatmeal, granola, etc.
meal:Dessert — cake, cookie, brownie, pudding, ice cream, tart, etc.
meal:Snack — dip, chips, popcorn, nachos, energy balls, etc.
meal:Beverage — smoothie, cocktail, juice, lemonade, etc.
meal:Lunch — sandwich, wrap, panini, grilled cheese, etc.
meal:Bread — bread, sourdough, focaccia, dinner roll, etc.
Uses word-boundary + optional-plural regex (\bWORD(?:s|es)?\b) so:
- "pancakes" matches the "pancake" pattern but "pancake" != "cake"
- "tartare" does not match "tart" (no word boundary after tart in tartare)
- "dipping" does not match "dip" (extra chars prevent boundary)
Title-only matching (not ingredient text) avoids false positives from
ingredient names like "cake flour" or "sandwich bread".
Estimated browse impact after backfill (--force on 3.19M recipes):
Breakfast: 43 → ~70k
Dessert: 372 → ~350k (real desserts, not flavor:Sweet)
Snack: 57 → ~60k
Beverage: 43 → ~36k
Lunch: 69 → ~26k