fix: chain redeploys onto a retired path's version history (#11029)

* fix: chain auto_parent onto the archived lineage tip at a path

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GoTAmRTjG2KAH4g4mco6T5

* fix: check descendants unscoped and drop the hash-guard move

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GoTAmRTjG2KAH4g4mco6T5

* fix: widen retired-path adoption, lock it, drop inherited grants

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KMhCSFeWSezY61g6woQiz2

* fix: check lineage linearity unscoped, under the parent lock

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GoTAmRTjG2KAH4g4mco6T5

* fix: do not name a lineage conflict the caller cannot read

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GoTAmRTjG2KAH4g4mco6T5

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Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>