feat(memory): scope Piri nunchi and MemPalace by audience

[seoseo-ai]

Summary

• route Piri transcript, Nunchi DB/snapshot/seen state, and MemPalace HOME through the same opaque private/shared audience
• make private recall private + shared + private-only legacy while shared recall remains shared-only
• add bounded owner-only Piri/MemPalace dispatchers, provider provenance, body-free status/doctor coverage, and deny tests
• keep the existing global collector behavior unchanged unless --audience-scoped <root> is enabled

Validation

• 145 focused bridge tests passed (plus 6 subtests)
• scoped private/shared/legacy materializer allow/deny tests passed
• Python compile, bash syntax, and git diff --check passed
• full harness static/compile stages passed locally; unrelated Termux-only baseline failures remain in hardlink and /usr/bin-fixed fixtures, so GitHub Linux CI is the merge gate

Rollout

After merge, use the already operator-approved order: bangtong pilot, then soonwook/jingun/dungae. This PR does not send a live provider canary.

Closes #950
Related: #948 #957 jinwon-int/piri#1