Fix ingest_traces array schema missing items property

VS Code 1.112+ validates that all MCP tool array-type parameters
include an "items" definition (microsoft/vscode#248810). The
ingest_traces tool's "traces" parameter was missing this, causing
startup failures.

Author: bingh0

src/mcp/mcp.c

@@ -304,7 +304,8 @@ static const tool_def_t TOOLS[] = {
      "\"sections\":{\"type\":\"array\",\"items\":{\"type\":\"string\"}}}}"},
 
     {"ingest_traces", "Ingest runtime traces to enhance the knowledge graph",
-     "{\"type\":\"object\",\"properties\":{\"traces\":{\"type\":\"array\"},\"project\":{\"type\":"
+     "{\"type\":\"object\",\"properties\":{\"traces\":{\"type\":\"array\",\"items\":{\"type\":"
+     "\"object\"}},\"project\":{\"type\":"
      "\"string\"}},\"required\":[\"traces\"]}"},
 };
 

tests/test_mcp.c

@@ -129,6 +129,35 @@ TEST(mcp_tools_list) {
     PASS();
 }
 
+TEST(mcp_tools_array_schemas_have_items) {
+    /* VS Code 1.112+ rejects array schemas without "items" (see
+     * https://github.com/microsoft/vscode/issues/248810).
+     * Walk every tool's inputSchema and verify that every "type":"array"
+     * property also contains "items". */
+    char *json = cbm_mcp_tools_list();
+    ASSERT_NOT_NULL(json);
+
+    /* Scan for all occurrences of "type":"array" — each must be followed
+     * by "items" before the next closing brace of that property. */
+    const char *p = json;
+    while ((p = strstr(p, "\"type\":\"array\"")) != NULL) {
+        /* Find the enclosing '}' for this property object */
+        const char *end = strchr(p, '}');
+        ASSERT_NOT_NULL(end);
+        /* "items" must appear between p and end */
+        size_t span = (size_t)(end - p);
+        char *segment = malloc(span + 1);
+        memcpy(segment, p, span);
+        segment[span] = '\0';
+        ASSERT_NOT_NULL(strstr(segment, "\"items\"")); /* array missing items */
+        free(segment);
+        p = end;
+    }
+
+    free(json);
+    PASS();
+}
+
 TEST(mcp_text_result) {
     char *json = cbm_mcp_text_result("{\"total\":5}", false);
     ASSERT_NOT_NULL(json);
@@ -1198,6 +1227,7 @@ SUITE(mcp) {
     /* MCP protocol helpers */
     RUN_TEST(mcp_initialize_response);
     RUN_TEST(mcp_tools_list);
+    RUN_TEST(mcp_tools_array_schemas_have_items);
     RUN_TEST(mcp_text_result);
     RUN_TEST(mcp_text_result_error);