URL-fix logic now lives once in sitecustomize._tc_fix_restic_cmd.
apply.sh's restic.py BLOCK delegates to it instead of repeating
the ~40-line implementation.
Additional safety: the BLOCK now guards its get_restic_config
reference with try/except NameError, so a future TrueNAS that
restructures restic.py won't cause an import error.
README: updated Backend table and disclaimer to reflect graceful
degradation; added "If TrueNAS adds native support" section that
covers all five upgrade scenarios (safe pass-through, base-class
shadowing risk, schema-change risk, etc.).
flan
8c0ffab166