refactor: remediation plan Fase 0-4 completata

- Fase 0: env var allineate, SYSTEM_PROMPT deduplicato, .gitignore pulito
- Fase 1: GameContext isolato, ciclo DM unificato, provider thread-safe (contextvars)
- Fase 2: DB schema esteso (current_area_id, combat_state, character_items)
- Fase 3: thread-local connection pool + WAL + busy_timeout
- Fase 4: test suite (32 test, 100% pass)
- heuristic_fallback come parser di riserva (non secondo pilota)

tests/test_dice.py

@@ -0,0 +1,108 @@
+import sys
+sys.path.insert(0, "src")
+
+from src.engine.dice import roll, dice_chain, roll_str, validate_die, ALL_DICE
+
+
+def test_roll_basic():
+    for _ in range(100):
+        r = roll("d20")
+        assert 1 <= r["total"] <= 20
+        assert r["die"] == "d20"
+        assert r["count"] == 1
+        assert r["modifier"] == 0
+        assert len(r["results"]) == 1
+
+
+def test_roll_multiple():
+    for _ in range(50):
+        r = roll("d6", count=3)
+        assert len(r["results"]) == 3
+        assert 3 <= r["total"] <= 18
+
+
+def test_roll_modifier():
+    r = roll("d20", modifier=5)
+    assert r["total"] == r["results"][0] + 5
+    assert r["modifier"] == 5
+
+
+def test_roll_crit():
+    for _ in range(1000):
+        r = roll("d20")
+        if r["results"][0] == 20:
+            assert r["crit"] is True
+        if r["results"][0] == 1:
+            assert r["fumble"] is True
+
+
+def test_roll_d100():
+    for _ in range(100):
+        r = roll("d%")
+        assert 1 <= r["total"] <= 100
+
+
+def test_roll_dice_chain_up():
+    res = dice_chain("d3", 2)
+    assert res["output_die"] == "d5"
+    assert res["steps"] == 2
+    assert res["input_die"] == "d3"
+
+
+def test_dice_chain_overflow():
+    res = dice_chain("d3", 20)
+    assert res["output_die"] == "d30"
+
+
+def test_dice_chain_underflow():
+    res = dice_chain("d30", -30)
+    assert res["output_die"] == "d3"
+
+
+def test_dice_chain_invalid():
+    res = dice_chain("d9", 1)
+    assert "error" in res
+
+
+def test_roll_str_basic():
+    r = roll_str("2d6+3")
+    assert r["count"] == 2
+    assert r["die"] == "d6"
+    assert r["modifier"] == 3
+
+
+def test_roll_str_percent():
+    r = roll_str("d%")
+    assert r["die"] == "d%"
+    assert r["count"] == 1
+
+
+def test_roll_str_negative_mod():
+    r = roll_str("d20-2")
+    assert r["modifier"] == -2
+
+
+def test_validate_die():
+    assert validate_die("d20") == "d20"
+    assert validate_die("d%") == "d%"
+    assert validate_die("d7") == "d7"
+    assert validate_die("d9") is None
+    assert validate_die("xyz") is None
+
+
+def test_all_dice_keys():
+    assert "d3" in ALL_DICE
+    assert "d20" in ALL_DICE
+    assert "d30" in ALL_DICE
+    assert "d%" in ALL_DICE
+    assert ALL_DICE["d%"] == 100
+
+
+def test_roll_zero_faced_die():
+    r = roll("d0")
+    assert r["total"] == 0
+
+
+def test_roll_one_faced_die():
+    r = roll("d1")
+    assert r["total"] == 1

tests/test_tools.py

@@ -0,0 +1,140 @@
+import sys
+import json
+sys.path.insert(0, "src")
+
+from src.engine.tools import run
+from src.engine.db import init_db, create_campaign, create_character, update_character
+
+
+def _setup_char():
+    conn = init_db()
+    camp_id = create_campaign("Test", "Avventura")
+    char_id = create_character(camp_id, "TestChar", "guerriero", "soldato")
+    update_character(
+        char_id,
+        level=1, str=15, agi=11, sta=14,
+        per=9, int=8, lck=10,
+        hp_current=12, hp_max=12, ac=15,
+        armor_type="light",
+    )
+    return camp_id, char_id
+
+
+def test_roll_dice_tool():
+    r = run("roll_dice", die="d20")
+    assert r["success"] is True
+    assert r["tool"] == "roll-dice"
+    assert 1 <= r["total"] <= 20
+
+
+def test_dice_chain_tool():
+    r = run("dice_chain", die="d3", steps=2)
+    assert r["success"] is True
+    assert r["output_die"] == "d5"
+
+
+def test_unknown_tool():
+    r = run("nonexistent")
+    assert r["success"] is False
+    assert "sconosciuto" in r["message"]
+
+
+def test_ability_check():
+    _, char_id = _setup_char()
+    r = run("ability_check", character_id=char_id, dc=12, modifier=2)
+    assert r["success"] is True
+    assert "d20" in r["message"]
+
+
+def test_saving_throw():
+    _, char_id = _setup_char()
+    r = run("saving_throw", character_id=char_id, save_type="Tempra", dc=15)
+    assert r["success"] is True
+    assert r["save_type"] == "Tempra"
+
+
+def test_saving_throw_invalid_type():
+    _, char_id = _setup_char()
+    r = run("saving_throw", character_id=char_id, save_type="Forza", dc=15)
+    assert r["success"] is False
+
+
+def test_movement():
+    r = run("movement", distance_m=30, terrain="normale")
+    assert r["success"] is True
+    assert r["rounds"] == 3
+    assert r["speed_m_per_round"] == 12
+
+
+def test_movement_difficult():
+    r = run("movement", distance_m=30, terrain="difficile")
+    assert r["success"] is True
+    assert r["rounds"] == 5
+
+
+def test_spellcasting():
+    _, char_id = _setup_char()
+    r = run("spellcasting", character_id=char_id, spell_name="Dardo Incantato", spell_check=18, dc=12)
+    assert r["success"] is True
+    assert r["result_tier"] in ("minore", "moderato", "maggiore")
+
+
+def test_spellcasting_failure():
+    _, char_id = _setup_char()
+    r = run("spellcasting", character_id=char_id, spell_name="Dardo Incantato", spell_check=5, dc=12)
+    assert r["success"] is True
+    assert "fallisce" in r["message"]
+
+
+def test_update_inventory():
+    _, char_id = _setup_char()
+    r = run("update_inventory", character_id=char_id, item="Pozione di Cura")
+    assert r["success"] is True
+    assert "Pozione di Cura" in r["message"]
+
+
+def test_award_xp():
+    _, char_id = _setup_char()
+    r = run("award_xp", character_id=char_id, xp=5)
+    assert r["success"] is True
+    assert r["xp_gained"] == 5
+
+
+def test_award_xp_levelup():
+    camp_id, _ = _setup_char()
+    # Create a lv0 character (contadino) to test level-up
+    import src.engine.db as db
+    lv0_id = db.create_character(camp_id, "Lv0 Hero", "contadino", "contadino")
+    db.update_character(lv0_id, level=0, xp=0)
+    r1 = run("award_xp", character_id=lv0_id, xp=10)
+    assert r1["xp_total"] == 10
+    assert r1["leveled_up"] is True
+
+
+def test_dm_override():
+    r = run("dm_override", command="narrate", params={"text": "Una luce accecante."})
+    assert r["success"] is True
+    assert r["tool"] == "dm-override"
+
+
+def test_dm_override_help():
+    r = run("dm_override", command="help")
+    assert r["success"] is True
+    assert "commands" in r
+
+
+def test_combat():
+    _, char_id = _setup_char()
+    r = run(
+        "combat",
+        character_id=char_id,
+        target_ac=15,
+        attack_bonus=2,
+        damage_die="d8",
+        mighty_deed_die="d3",
+        luck_mod=0,
+        armor_type="medium",
+    )
+    assert r["success"] is True
+    assert r["tool"] == "combat"
+    assert isinstance(r["hit"], bool)