perf(mcp): deduplicate operation schemas with shared definitions

Share operation definitions between individual requests and batch steps, reducing the execute request schema by 39%. Place definitions at the tool input schema root so local references resolve correctly.

Update the schema digest and smoke assertions. Verified with 45 MCP tests, the live stdio smoke test, and 228 schema validation comparisons.

src/mcp_ops.rs

@@ -935,26 +935,20 @@ fn ty_schema(ty: &Ty) -> Value {
 }
 
 pub fn shared_defs() -> Value {
-    let batch_variants: Vec<Value> = OPS
-        .iter()
-        .filter(|op| op.batchable)
-        .map(|op| op_schema(op))
-        .collect();
-
-    json!({
+    let mut defs = json!({
         "point":  {"type": "array", "items": {"type": "number"}, "minItems": 2, "maxItems": 3},
         "window": {"type": "array", "items": {"type": "number"}, "minItems": 4, "maxItems": 4},
         "handle": {"type": "string", "pattern": "^(0[xX])?[0-9A-Fa-f]+$"},
-        "batch_step": {
-            "type": "object",
-            "properties": {
-                "op": {"type": "string"},
-                "document_id": {"type": "integer", "minimum": 0}
-            },
-            "required": ["op"],
-            "anyOf": batch_variants
-        }
-    })
+        "batch_step": batch_step_schema()
+    });
+    for op in OPS {
+        defs[format!("op_{}", op.name)] = op_schema(op);
+    }
+    defs
+}
+
+fn op_ref(op: &OpDef) -> Value {
+    json!({"$ref": format!("#/$defs/op_{}", op.name)})
 }
 
 fn rules_text(op: &OpDef) -> String {
@@ -996,7 +990,7 @@ pub fn op_schema(op: &OpDef) -> Value {
 }
 
 pub fn execute_request_schema() -> Value {
-    let variants: Vec<Value> = OPS.iter().map(|op| op_schema(op)).collect();
+    let variants: Vec<Value> = OPS.iter().map(|op| op_ref(op)).collect();
     let op_names: Vec<&str> = OPS.iter().map(|op| op.name).collect();
     json!({
         "$schema": "https://json-schema.org/draft/2020-12/schema",
@@ -1021,7 +1015,7 @@ pub fn batch_step_schema() -> Value {
     let batch_variants: Vec<Value> = OPS
         .iter()
         .filter(|op| op.batchable)
-        .map(|op| op_schema(op))
+        .map(|op| op_ref(op))
         .collect();
 
     json!({