feat(data): transpose Foundry PC sheets into data/pcs

All 8 sheets from fiches_personnages/ converted to the strict Combatant
JSON schema (data/monsters convention) so the CLI can run PCs directly:

  --side players data/pcs/esha.json

- id derived from the file stem; source field points at the original sheet
- oni: placeholder attacks without encoded damage ('une Pioche', 'Weapon')
  left out, documented in notes (pick stats ambiguous light/heavy in the
  rules KB; no identification possible for 'Weapon')
- README: PC section now documents data/pcs usage
- tests: parametrized load check + golden spots for the 8 PC files

data/pcs/esha.json

@@ -0,0 +1,85 @@
+{
+  "name": "Esha Randu",
+  "level": 4,
+  "size": "Medium",
+  "abilities": {
+    "str_score": 14,
+    "dex_score": 18,
+    "con_score": 14,
+    "int_score": 16,
+    "wis_score": 12,
+    "cha_score": 9
+  },
+  "hp_max": 32,
+  "ac": {
+    "total": 19,
+    "touch": 15,
+    "flat_footed": 14
+  },
+  "bab": 4,
+  "initiative_mod": 5,
+  "speed_land_ft": 25,
+  "saves": {
+    "fort": 6,
+    "ref": 10,
+    "will": 5
+  },
+  "attacks": [
+    {
+      "name": "Lance",
+      "kind": "melee",
+      "attack_bonus": 7,
+      "damage": [
+        {
+          "formula": "1d8",
+          "types": [
+            "piercing"
+          ]
+        }
+      ],
+      "damage_bonus": 4,
+      "crit_range": 20,
+      "crit_mult": 3,
+      "reach_ft": 10,
+      "count": 1
+    },
+    {
+      "name": "Composite Shortbow +3",
+      "kind": "ranged",
+      "attack_bonus": 9,
+      "damage": [
+        {
+          "formula": "1d6",
+          "types": [
+            "piercing"
+          ]
+        }
+      ],
+      "damage_bonus": 3,
+      "crit_range": 20,
+      "crit_mult": 3,
+      "reach_ft": 5,
+      "count": 1,
+      "range_increment_ft": 70
+    },
+    {
+      "name": "Earth Breaker",
+      "kind": "melee",
+      "attack_bonus": 8,
+      "damage": [
+        {
+          "formula": "2d6",
+          "types": [
+            "bludgeoning"
+          ]
+        }
+      ],
+      "damage_bonus": 4,
+      "crit_range": 20,
+      "crit_mult": 3,
+      "reach_ft": 5,
+      "count": 1
+    }
+  ],
+  "source": "fiches_personnages/esha_sheet.json"
+}