fix: close failed Docker probes and finalize Beads projections - #63

Corrective round after PR #62. Finalizes the static Beads 1.2.2 projections, merges current 0.12.0-dev with an explicit no-FF merge, closes Docker SDK sessions on failed daemon probes, and conditionally skips only tests marked docker when the daemon is unavailable.

Validation in standalone worktree:

• make check WHAT=all: 7/7 gates green, including Pyrefly 1.2.0
• make test WHAT=all after canonical testmon cache clear: 457 passed, 2 expected Docker-unavailable skips
• make gen WHAT=check remains blocked by the old generator attempting runtime Beads ledger inspection; this is owned by the active flext-infra static-projection cutover and is not bypassed here.

Summary by cubic

Fixes Docker integration test probing so failed daemon probes close the SDK session, and finalizes the Beads 1.2.2 projections.

• When the Docker daemon is unreachable, only tests marked docker are skipped; other connectivity tests still run.
• The Beads tool now pins to github:gastownhall/beads 1.2.2 and the issue prefix changes from mro to flext.
• make test WHAT=all passes 457 tests with 2 expected Docker-unavailable skips.

^{Written for commit e808891. Summary will update on new commits.}