setupPath() guarded its profile append on the binDir value it was about
to write, which is blind to accumulation across different Mosaic homes:
every wizard run against a fresh temp home appended a permanent # Mosaic
block to the operator's real shell profile (1,061 measured appends on
sb-it-1-dt, naming 1,058 unique /tmp dirs of which zero exist).
- S1/S5: managed block between >>> mosaic begin/end <<< sentinels,
rewritten in place, both the POSIX and $env:Path arms
- S2: a target home that is not the resolved default skips the profile
write entirely; a test harness can no longer touch the operator profile
- S3: byte-identical profile across repeated runs (any homes)
- S4: legacy unmarked # Mosaic pairs collapse into the managed block
S2 arm captured RED against pre-fix code (expected 'skipped', got
'added'), then GREEN post-fix; full suite 1585 passed.
code-infra-01