Add claude-opus-4-7 pricing; fix populate-pricing script path

scripts/populate-pricing.py still pointed at backend/core/provider_pricing.json,
which was deleted in the dedupe commit. Retarget to eval_mcp/core/ (the
canonical location) and add claude-opus-4-7 to the Anthropic model list.
The JSON change mirrors what the script would regenerate.

Author: DataGomes

eval_mcp/core/provider_pricing.json

@@ -324,6 +324,10 @@
     }
   },
   "anthropic": {
+    "claude-opus-4-7": {
+      "input": 5.0,
+      "output": 25.0
+    },
     "claude-opus-4-6": {
       "input": 5.0,
       "output": 25.0

scripts/populate-pricing.py

@@ -25,7 +25,7 @@
 
 SCRIPT_DIR = Path(__file__).parent
 PROJECT_DIR = SCRIPT_DIR.parent
-PRICING_FILE = PROJECT_DIR / "backend" / "core" / "provider_pricing.json"
+PRICING_FILE = PROJECT_DIR / "eval_mcp" / "core" / "provider_pricing.json"
 
 # Models to include per provider. Add new models here as they're released.
 OPENAI_MODELS = [
@@ -42,6 +42,7 @@
 ]
 
 ANTHROPIC_MODELS = [
+    "claude-opus-4-7",
     "claude-opus-4-6",
     "claude-sonnet-4-6",
     "claude-opus-4-5",