* fix(ci): keep the pre-merge check off the report-mode failures
* fix(ci): fail the pre-merge check in block mode without a base commit
* fix(ci): report every pre-merge failure the way its mode asks
The merge step now separates a base commit it cannot fetch from a merge it
cannot do, both failures print an annotation, and a spec pins the mode
wiring of the three Policy workflows.
* test(ci): type the Policy workflow assertions
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Co-authored-by: imccyu <[email protected]>
