taurus v0.11.1

Fix — segfault under tight parse loops (#256)

taurus_parse_string could segfault under tight parse/free cycles
(Ruby benchmark-ips with delayed GC). Root cause: the thread-local
g_current_document retained a dangling pointer to the returned
document after the caller freed it, corrupting overflow-table
cleanup for subsequent parses.

Fix: clear g_current_document (call
taurus_compact_set_current_document(NULL)) on the direct_parse
success path, not just on failure. The thread-local is now NULL
between parse cycles, preventing stale-pointer contamination of
the compact-pointer overflow table.

483/483 tests pass on macOS + Linux; ASAN clean.