[PIR][WP3] Map LiveMem/TARL three-tier memory onto ruvllm context modules + ruvector-agent-memory

Epic: #837 · Plan: docs/research/perpetual-intelligence-runtime/03-program-plan.md

Goal

Formalize the three-tier memory architecture by mapping existing modules onto LiveMem's design, rather than building new tiers from scratch:

The work is making the tiering explicit, documented, and testable, not inventing storage.

Evidence

LiveMem — arXiv:2608.02515, submitted 2026-08-03. A fixed-capacity memory state whose lifetime is independent of the active context, maintained via a parallel memory branch (Gated DeltaNet-2 backbone) alongside a bounded KV attention window. Reframes long-running inference as computational state preservation rather than context growth: the system can answer from memory state after the supporting evidence has left the context window.

Disambiguation: cite as "LiveMem (arXiv:2608.02515)" — unrelated to the consumer iOS app of the same name.

Acceptance criteria

• Each tier has a documented interface, with the promotion/demotion policy between tiers stated explicitly.
• A test proves state survives context eviction — the system answers correctly from tier 2 after the supporting evidence has been evicted from working context. This is LiveMem's core claim and the single most important criterion here.
• Tier 2 has a hard fixed capacity enforced structurally; a test demonstrates it does not grow with context length over a long-running session.
• The existing module mapping above is verified against the code rather than assumed — if episodic_memory/semantic_cache/agentic_memory do not actually compose into a single fixed-capacity tier, say so and scope the delta.
• ADR-252 and ADR-211 are cited by filename, not number alone — ruvector's ADR set has ~15+ duplicate numbers under remediation in WP0a.
• No persistence path is introduced that bypasses the proof-gated writes WP4 builds on.

Dependencies

WP1 (#847). Blocks WP4 (#840), and transitively WP12.

Start with docs/research/perpetual-intelligence-runtime/03-program-plan.md and inspect the existing ruvllm working_memory, episodic_memory, semantic_cache, agentic_memory, ruvector-agent-memory, reasoning_bank, and ruvector-temporal-coherence modules. Verify whether the proposed mapping forms a fixed-capacity tier and identify the ADR-252 and ADR-211 filenames. Done means documented interfaces and promotion/demotion rules, tests for survival after context eviction and fixed capacity, and no bypass of proof-gated writes.