Add on-demand meal-log health/calorie analyzer + git-sync README trap pitfall

- scripts/analyze_history.py: read-only per-meal/per-day kcal+protein+micronutrient review
  of meal-history.json, unit-aware via references/nutrition-db.json (g_per_unit conversion so
  veg logged in g vs count both resolve correctly)
- references/nutrition-db.json: estimate per-item nutrition DB (ESTIMATE-grade; condiments/oil
  not logged => ~+80-120 kcal/meal real)
- SKILL.md: 'Health / calorie review (on-demand)' section; 'Git-sync README trap' pitfall
  (live README may be a stub while repo README is the real doc -- safe-sync procedure);
  scripts + references pointers

references/calories.md

@@ -0,0 +1,60 @@
+# Calorie & macro estimates (per logged portion)
+
+Rough, food-database-style estimates used by `scripts/calc_meal.py` to show per-meal
+calories and to enforce the RATIONAL PORTIONS rule (incl. the 1000 kcal/meal cap).
+These are SUGGESTED-meal estimates — they exclude cooking oil/butter/condiments that
+are NOT logged in meal-history.json, so real cooked calories run ~80–150 kcal higher
+per cooked meal. Label any shown figure as "est." Not medical/dietitian-grade.
+
+`kcal_per` is the value for the portion unit used in meal-history.json:
+- count / can / portion / bulb / tub / jar / pack / loaf / serving → whole item
+- g / ml → per gram (× qty)
+
+## Animal (non-red-meat)
+- Eggs — 70 kcal each (count)
+- Chicken breast — 165 kcal (count ~1 breast / ~120g)
+- Tinned tuna in veg oil — 190 kcal (can, drained+oil)
+- Tinned tuna in spring water — 130 kcal (can)
+- Tinned green lentils — 230 kcal (can)
+- Greek yogurt (0%) — 50 kcal / 100g
+- Cottage cheese — 95 kcal / 100g
+- Cheese — 400 kcal / 100g
+- Halloumi — 320 kcal / 100g
+- Whey protein powder — 4 kcal / g (i.e. 200 kcal per 50g)
+- Milk (semi) — 0.5 kcal / ml
+
+## Plant / grain / legume
+- Dried red lentils — 3.5 kcal / g (dry)
+- Baked beans — 200 kcal / can
+- Chickpeas — 180 kcal / can
+- Tofu (firm) — 1.4 kcal / g
+- Edamame (frozen) — 1.2 kcal / g
+- Wholemeal pasta — 350 kcal / serving
+- Microwave rice — 220 kcal / portion
+- Scottish oats — 3.7 kcal / g
+
+## Veg (mostly low-cal, high volume)
+- Broccoli — 35 kcal (count ~1 head half)
+- Carrots — 0.41 kcal / g
+- Courgette — 20 kcal (count)
+- Sweet potatoes — 130 kcal (count)
+- Aubergine — 40 kcal (count)
+- Red cabbage — 40 kcal (count)
+- Cauliflower — 30 kcal (count)
+- Leeks — 55 kcal (count)
+- Mushrooms — 0.23 kcal / g
+- Lettuce — 15 kcal (count)
+- Salad tomatoes — 15 kcal (count)
+- Orange bell pepper — 30 kcal (count)
+- Small white onions — 15 kcal (count)
+- Frozen mixed veg — 0.73 kcal / g
+- Peeled plum tomatoes — 90 kcal (can)
+
+## Red meat (in-stock only, never bought)
+- Cumberland sausages — 55 kcal (count)
+- Lamb mince — 2.5 kcal / g
+
+## Calorie cap (RATIONAL PORTIONS)
+Each meal must stay at or under **1000 kcal** (est., excluding unlogged cooking fat).
+If a capped+balanced meal would exceed 1000 kcal, reduce starch/cheese/halloumi/lentil
+portions (not protein) until it fits — or it's a sign the plate is too starch-heavy.