tests: add functional tests for DB message persistence, rebalance groups

Add backend-agnostic functional tests for database message persistence.
All tests work with both SQLite and flat-file backends.

New tests in test_history.c:
- message_db_history_on_reopen: basic incoming write+read round-trip
- message_db_history_multiple: 3 messages from different resources
- message_db_history_contact_isolation: buddy1 msg absent from buddy2
- message_db_history_special_chars: XML entities survive decode+DB
- message_db_history_outgoing: sent message persists across reopen
- message_db_history_dialog: outgoing + incoming both in history
- message_db_history_empty: no crash on contact with no history
- message_db_history_long_message: 1000+ char body not truncated
- message_db_history_newline: embedded LF stored correctly
- message_db_history_service_chars: backslash pipe percent braces etc
- message_db_history_verify: /history verify (ifdef HAVE_HISTORY_VERIFY)
- message_db_history_lmc: XEP-0308 correction replaces original in DB

Rebalance test groups for parallel execution (19/22/22/21):
- Group 1: Connect, Ping, Rooms, Software, LastActivity
- Group 2: Message, Receipts, Roster, DB History
- Group 3: Chat Session, Presence, Disconnect
- Group 4: MUC, Carbons

tests/functionaltests/functionaltests.c

@@ -16,7 +16,7 @@
  *
  * Tests are organized into groups for better maintainability and parallel execution:
  *   Group 1: Connect, Ping, Rooms, Software, Last Activity  (19 tests)
- *   Group 2: Message, Receipts, Roster, DB History           (23 tests)
+ *   Group 2: Message, Receipts, Roster, DB History           (22 tests)
  *   Group 3: Chat Session, Presence, Disconnect              (22 tests)
  *   Group 4: MUC, Carbons                                    (21 tests)
  *
@@ -147,7 +147,9 @@ main(int argc, char* argv[])
         PROF_FUNC_TEST(message_db_history_long_message),
         PROF_FUNC_TEST(message_db_history_newline),
         PROF_FUNC_TEST(message_db_history_service_chars),
+#ifdef HAVE_HISTORY_VERIFY
         PROF_FUNC_TEST(message_db_history_verify),
+#endif
         PROF_FUNC_TEST(message_db_history_lmc),
     };
 

tests/functionaltests/test_history.c

@@ -385,6 +385,7 @@ message_db_history_service_chars(void **state)
     assert_true(prof_output_exact("svc: a\\b c|d e%f {g} [h] i=j"));
 }
 
+#ifdef HAVE_HISTORY_VERIFY
 /*
  * Test: /history verify reports no issues after normal message writes.
  */
@@ -415,6 +416,7 @@ message_db_history_verify(void **state)
     prof_input("/history verify");
     assert_true(prof_output_exact("Verification complete: no issues found."));
 }
+#endif /* HAVE_HISTORY_VERIFY */
 
 /*
  * Test: LMC (Last Message Correction, XEP-0308) — incoming correction

tests/functionaltests/test_history.h

@@ -8,5 +8,7 @@ void message_db_history_empty(void **state);
 void message_db_history_long_message(void **state);
 void message_db_history_newline(void **state);
 void message_db_history_service_chars(void **state);
+#ifdef HAVE_HISTORY_VERIFY
 void message_db_history_verify(void **state);
+#endif
 void message_db_history_lmc(void **state);