bv v0.20.0

Features

• --id-pattern (#188): custom bead-ID regex for trackers whose IDs lack a
  numeric suffix, so correlation works with non-standard ID schemes out of the
  box.

Fixes

• bd embedded Dolt workspaces are first-class (#189): the loader now treats
  bd's embedded Dolt workspace layout as a real datasource instead of falling
  through to an unhelpful error; robot-mode surfaces work against Dolt-backed
  beads databases.
• Actionable bd-export error message: failures during bd export now say
  what went wrong and what to do about it, instead of a bare error.

Tests

• Pinned regression coverage for the #188 and #189 behaviors.