M1b: survival stats, day/night, fire fuel, cooking, foraging, torches, death + grave

- Health, stamina, hunger, warmth and wet with HUD bars, status tags and clock
- 20-minute day/night cycle with moon, stars and lit clouds
- Campfire fuel (2 min start, 15 min max), heat radius, cooking needs a lit fire
- Berry bushes (regrow 10 min), mushrooms, roasted mushroom, torch
- Stamina costs for sprint, jump and harvest hits
- Death respawns at island start and leaves a grave bag
- Saves include stats, time of day, fire fuel, regrowth timers and graves
- New test_survival_stats suite; tests fail if a script error aborts them

docs/ROADMAP.md

@@ -23,10 +23,13 @@ actually run and see. Timelines assume solo dev + heavy AI assistance, steady
 
 ## M1 — Survival loop (single-player) · ~3–5 weeks
 **Goal:** the core game verbs.
-- [ ] Resource nodes: chop tree → wood, mine rock → stone
-- [ ] Inventory + simple hotbar UI
-- [ ] Crafting (recipe: wood → tools / building pieces)
-- [ ] Health / stamina, day-night cycle
+Detailed plan in `docs/SURVIVAL_DESIGN.md` (phases M1a–M1d).
+- [x] Resource nodes: chop tree → wood, mine rock → stone *(M1a)*
+- [x] Inventory + simple hotbar UI, chests *(M1a)*
+- [x] Crafting (recipe: wood → tools / building pieces) *(M1a)*
+- [x] Pause menu, title screen, world slots, save/load, autosave *(M1a)*
+- [x] Health / stamina / hunger / warmth, day-night cycle, fire fuel, cooking, foraging, torches, death + grave *(M1b)*
+- [ ] Weather (rain, storm, snow), wet/shelter *(M1c)*
 - [ ] Snap-together building: place a wall/floor, resource cost, basic support rule
 - **Done when:** gather → craft → build a tiny shelter, single-player.