fix(doctor): discover historical Workshop workspace setup (#145084)

fix(doctor): discover historical Workshop workspace setup (#145084)

Updates and `openclaw doctor --fix` no longer refuse the Skill Workshop migration when retained proposals reference a former workspace whose valid setup file was skipped by discovery. Historical roots are imported through the existing guarded importer before their Workshop records migrate; unusable historical roots resolve with a warning instead of a refusal while configured-workspace failures and recovery safeguards remain blocking.

Surface: Doctor state migrations during update.

Fixes #145050. Thanks to @compoodment for the report and the red-phase reproduction in #145066, which this fix supersedes.