TAP MCP client: port PR5372 coverage to MCP profiles/target_id routing model

This commit ports the TAP MCP client test coverage from PR #5372 to the new MCP profiles architecture, replacing legacy direct backend variable assumptions with target/profile-based routing.

What was updated:
- Reworked test setup to use `mcp_target_profiles` + `mcp_auth_profiles` rather than legacy `mcp-mysql_*` config variables.
- Updated MCP request payloads and helper flows to route via `target_id`.
- Aligned assertions with profile-backed runtime behavior and removed obsolete expectations tied to static mysql host/user/password globals.

Why this was needed:
- The previous tests were written before MCP target/profile routing existed.
- Without this update, TAP coverage would exercise deprecated paths and miss regressions in the current MCP execution model.

Result:
- Test suite now validates the same functional intent as PR #5372 but against the current profile-driven MCP routing implementation.

Author: renecannao

test/tap/groups/groups.json

@@ -259,6 +259,7 @@
   "genai_embedding_rerank-t": [ "ai-g1" ],
   "genai_module-t": [ "ai-g1" ],
   "mcp_module-t": [ "ai-g1" ],
+  "mcp_query_run_sql_readonly-t": [ "ai-g1" ],
   "nl2sql_integration-t": [ "ai-g1" ],
   "nl2sql_internal-t": [ "ai-g1" ],
   "nl2sql_model_selection-t": [ "ai-g1" ],

test/tap/tap/Makefile

@@ -59,14 +59,17 @@ utils_mysql8.o: utils.cpp cpp-dotenv/static/cpp-dotenv/libcpp_dotenv.a libcurl.s
 tap.o: tap.cpp cpp-dotenv/static/cpp-dotenv/libcpp_dotenv.a libcurl.so -lssl -lcrypto libcpp_dotenv.so
 	$(CXX) -fPIC -c tap.cpp $(IDIRS) $(OPT)
 
-libtap_mariadb.a: tap.o command_line.o utils_mariadb.o cpp-dotenv/static/cpp-dotenv/libcpp_dotenv.a
-	ar rcs libtap_mariadb.a tap.o command_line.o utils_mariadb.o $(SQLITE3_LDIR)/sqlite3.o $(PROXYSQL_LDIR)/obj/sha256crypt.oo
+mcp_client.o: mcp_client.cpp mcp_client.h libcurl.so
+	$(CXX) -fPIC -c mcp_client.cpp $(IDIRS) $(OPT)
 
-libtap_mysql57.a: tap.o command_line.o utils_mysql57.o cpp-dotenv/static/cpp-dotenv/libcpp_dotenv.a
-	ar rcs libtap_mysql57.a tap.o command_line.o utils_mysql57.o $(SQLITE3_LDIR)/sqlite3.o $(PROXYSQL_LDIR)/obj/sha256crypt.oo
+libtap_mariadb.a: tap.o command_line.o utils_mariadb.o mcp_client.o cpp-dotenv/static/cpp-dotenv/libcpp_dotenv.a
+	ar rcs libtap_mariadb.a tap.o command_line.o utils_mariadb.o mcp_client.o $(SQLITE3_LDIR)/sqlite3.o $(PROXYSQL_LDIR)/obj/sha256crypt.oo
 
-libtap_mysql8.a: tap.o command_line.o utils_mysql8.o cpp-dotenv/static/cpp-dotenv/libcpp_dotenv.a
-	ar rcs libtap_mysql8.a tap.o command_line.o utils_mysql8.o $(SQLITE3_LDIR)/sqlite3.o $(PROXYSQL_LDIR)/obj/sha256crypt.oo
+libtap_mysql57.a: tap.o command_line.o utils_mysql57.o mcp_client.o cpp-dotenv/static/cpp-dotenv/libcpp_dotenv.a
+	ar rcs libtap_mysql57.a tap.o command_line.o utils_mysql57.o mcp_client.o $(SQLITE3_LDIR)/sqlite3.o $(PROXYSQL_LDIR)/obj/sha256crypt.oo
+
+libtap_mysql8.a: tap.o command_line.o utils_mysql8.o mcp_client.o cpp-dotenv/static/cpp-dotenv/libcpp_dotenv.a
+	ar rcs libtap_mysql8.a tap.o command_line.o utils_mysql8.o mcp_client.o $(SQLITE3_LDIR)/sqlite3.o $(PROXYSQL_LDIR)/obj/sha256crypt.oo
 
 libtap.so: libtap_mariadb.a cpp-dotenv/dynamic/cpp-dotenv/libcpp_dotenv.so libre2.so
 	$(CXX) -shared -o libtap.so -Wl,--whole-archive libtap_mariadb.a -Wl,--no-whole-archive $(LWGCOV)
@@ -123,4 +126,3 @@ cleanall: clean
 	# Remove cpp-dotenv source directories (213MB)
 	cd cpp-dotenv/static && rm -rf cpp-dotenv-*/ || true
 	cd cpp-dotenv/dynamic && rm -rf cpp-dotenv-*/ || true
-

test/tap/tap/command_line.cpp

@@ -39,6 +39,8 @@ CommandLine::~CommandLine() {
 		free(admin_username);
 	if (admin_password)
 		free(admin_password);
+	if (mcp_auth_token)
+		free(mcp_auth_token);
 
 	if (mysql_host)
 		free(mysql_host);
@@ -236,6 +238,20 @@ int CommandLine::getEnv() {
 			replace_str_field(&this->admin_password, value);
 	}
 
+	{
+		// proxysql mcp connection
+		value = getenv("TAP_MCP_PORT");
+		if (value) {
+			env_port = strtol(value, NULL, 10);
+			if (env_port > 0 && env_port < 65536)
+				mcp_port = env_port;
+		}
+
+		value = getenv("TAP_MCP_AUTH_TOKEN");
+		if (value)
+			replace_str_field(&this->mcp_auth_token, value);
+	}
+
 	{
 		// mysql admin connection
 		value = getenv("TAP_MYSQLHOST");

test/tap/tap/command_line.h

@@ -32,6 +32,10 @@ class CommandLine {
 	char* admin_username = strdup("admin");
 	char* admin_password = strdup("admin");
 
+	// proxysql mcp connection
+	int mcp_port = 6071;
+	char* mcp_auth_token = strdup("");
+
 	// mysql admin connection
 	char* mysql_host = strdup("127.0.0.1");
 	int mysql_port = 3306;
@@ -69,4 +73,3 @@ class CommandLine {
 };
 
 #endif // #ifndef COMMAND_LINE_H
-