memtrack: check_free_resolved_address treats an untracked address as safe (SD-06) #37

map2check_check_free_resolved_address treats an address with no memory record as a safe free, while map2check_check_free reports MEMSAFETY_FREE for the same address. Documented as SD-06 in docs/semantic-deltas.md (PR #35).

Reproduce (links against libmap2check.a, no features):

map2check_init();
map2check_check_free_resolved_address((void *)0x5000, 3, "main", 0);  /* None */
map2check_check_free("p", (void *)0x5000, 0, 4, "main");             /* MemsafetyFree */

Legacy: is_invalid_free returns TRUE for an address that is not found (lib_old/ListLog.c:95-118 on origin/refactory_memory_log), and map2check_free_resolved_address uses it (lib_old/AnalysisModeMemtrack.c:164-183).

Likely cause: is_invalid_free_resolved in rust/src/memtrack/mod.rs ends with .unwrap_or(false).

Pinned today by: rust/src/analysismode/memory.rs::free_resolved_checker_outcomes (the 0x9999 case).

Acceptance criteria:

• Decide the contract for an untracked address (Add differential tests against the C implementation #15 can confirm the legacy verdict).
• If it becomes an invalid free: change is_invalid_free_resolved, update the test, SD-06 in docs/semantic-deltas.md and the map2check_check_free_resolved_address section of docs/api-deltas.md.