MM-25: Add MemoryPropose host gate and full profile lifecycle

Parent

#771

Checkpoint

MC-7 Durable memory lifecycle

What to build

Expose a host-gated MemoryPropose tool and complete approve, reject, archive, restore, supersede, conflict, delete, and tombstone propagation through recall.

Acceptance criteria

• Renderer/model input cannot forge approval.
• Active entries always contain confirmation and source refs.
• Delete creates a tombstone and cannot resurrect through consolidation/cache.
• Recall respects conflict, freshness, and lifecycle states.
• Incognito and permission denial block proposals and writes.

Required tests

• Host permission
• lifecycle matrix
• delete resurrection
• concurrent proposals
• invalid/rate-limited tool input

Benchmark

Full 80-case lifecycle dataset; pass >=95%, privacy 100%, false promotion and delete resurrection zero.

Blocked by

• [MM-24] Add evidence-gated profile proposal consolidation #804 (MM-24)
• [MM-09] Add deterministic bounded MemorySegmentBuilder #788 (MM-09)

Rollout and rollback

Disable agent proposal tool; retain manual host proposal/approval and structured records.