feat(conditions): add blinded/invisible/helpless/fascinated combat rules

src/pf1e_simulator/conditions.py

@@ -217,6 +217,20 @@ ASLEEP = Condition(
 )
 
 
+# Helpless: helpless for all intents, treated as Dex 0 (loses Dex to AC),
+# can't act; melee attackers gain +4 (engine logic in resolve_attack) (CRB)
+HELPLESS = Condition(
+    name="helpless",
+    denies_dex_to_ac=True,
+    cant_act=True,
+)
+
+# Fascinated: distracted, takes no actions other than paying attention (CRB)
+FASCINATED = Condition(
+    name="fascinated",
+    cant_act=True,
+)
+
 # Grappled: -4 Dex, -2 attack, no movement, no AoO, can't cast without concentration (CRB)
 GRAPPLED = Condition(
     name="grappled",
@@ -267,6 +281,13 @@ DISPLACED = Condition(
     miss_chance=50,
 )
 
+# Invisible: total concealment against attacks targeting it; the attacker-side
+# +2 on attack rolls and the target's lost Dex bonus are engine logic (CRB)
+INVISIBLE = Condition(
+    name="invisible",
+    miss_chance=50,
+)
+
 # ── Registry ─────────────────────────────────────────────────────────────────
 CONDITIONS_BY_NAME: dict[str, Condition] = {
     c.name: c
@@ -275,5 +296,6 @@ CONDITIONS_BY_NAME: dict[str, Condition] = {
         BLINDED, DEAFENED, FLAT_FOOTED, PRONE, STUNNED, PARALYZED,
         NAUSEATED, DAZED, STAGGERED, FRIGHTENED, PANICKED, COWERING,
         ASLEEP, GRAPPLED, PINNED, BLURRED, DISPLACED,
+        HELPLESS, FASCINATED, INVISIBLE,
     ]
 }