feat: agent memory tools — inscribe, recall, entropy query via MCP

[stackbilt-admin]

Context

tarotscript#141 introduced memory-as-deck for agents. The memory deck is dynamically populated via inscribe and queried via dignity-weighted draws. MCP gateway needs tools for external consumers to interact with agent memory.

Tools needed

• agent_inscribe — write a structured memory card into an agent's Discard zone (normal mode) or Deck (flash mode for crisis-critical)
• agent_recall — dignity-weighted draw from agent memory deck, filtered by element/tier/tags
• agent_entropy — query cognitive health metrics (Shannon diversity, element depletion, TRANS capacity)
• agent_memory_status — zone card counts (discard/deck/meta-insight), reservation count

Upstream

• agent_memory_deck contract in tarotscript src/deck/contracts.ts
• Three-zone lifecycle: Discard → Deck → Meta-Insight
• inscription_mode: "normal" | "flash" on memory cards
• typed-swap convergence: hot/cold/swap containers map to zones