fix: preserve pathless batch recovery semantics

[chubes4]

Summary

• preserve keyed, nested, JSON, and serialized Action Scheduler argument decoding when identifying active batch parents
• use the canonical jobs-table constant in pathless recovery
• share nested argument extraction without introducing audit duplication
• retain the verified scheduler/drain formatting from the post-fix: restore high-volume batch queue liveness #3063 corrections

Context

Follow-up to #3063 and clean final-tree replacement for #3064. This single commit avoids Homeboy issue Extra-Chill/homeboy#12006, where candidate lint retains superseded findings from intermediate commits.

Verification

• scoped Homeboy lint: pass, zero findings
• scoped Homeboy audit: pass, zero introduced findings
• focused pipeline batch PHPUnit: pass
• recovery active-action guard smoke: 15/15 pass
• batch v2 contract smoke: pass

Safety

No queue limits, cleanup, release, deployment, or live database mutations. High-volume fan-out remains unchanged.