v0.20.0

The localharness CLI grows real agent-to-agent reach. Agent-to-agent call
no longer pretends to be an HTTP endpoint — it runs headlessly through the
credit proxy and answers as the target agent.

Added

• Headless call via the credit proxy — call [--as me] <name> <msg> runs
  an agent turn in-process, reaching Gemini through the proxy authenticated by
  the caller's identity key (personal-sign; spends the caller's $LH, opens a
  free session lazily). No model key, no live browser tab, no relay server.
• On-chain personas — persona <name> <text|file> publishes a subdomain's
  public system prompt under keccak256("localharness.persona")
  (registry::persona_of / encode_set_persona); call runs under the
  target's persona so it answers as that agent (generic fallback when unset).
• Persistent conversations — call saves history per (caller, target) to
  .localharness/history/ and resumes it on the next call; --fresh starts a
  new thread. threads lists saved conversations; forget <name|--all> drops
  them (local files only — never identity keys or on-chain state).
• Richer whoami — owner, tokenId, token-bound wallet, persona-published
  flag, and public-face choice (all read-only RPC). --json for machine output.
• list (alias mine) — enumerate the subdomains the caller owns
  (name / tokenId / token-bound wallet); --json for machine output. CLI
  parity with the browser's list_subdomains tool.
• version / --version — print the installed CLI version.
• compile <src.rl> [out.wasm] — compile-check a rustlite cartridge
  locally (and optionally emit the wasm) with NO on-chain write, so authors
  iterate before spending a sponsored publish. Plus scripts/validate-cartridge .js, which instantiates a compiled cartridge with stub host imports and
  drives a few frames to catch runtime traps a static compile can't.
• bitmask.rl — a Bitmask Composer cartridge (the live public face of
  claude.localharness.xyz): click 16 bit-cells to toggle, read DEC/HEX,
  shift/clear/invert. A worked example of an interactive, stateful, on-chain
  dev tool in rustlite.

Changed

• call is now headless-via-proxy and answers as the target's published
  persona; the previous POST .../?rpc=1 framing was non-functional (the
  ?rpc=1 endpoint is browser postMessage, not HTTP — a static host 405s a
  POST). llms.txt / skill.md corrected to document the two real transports.
• registry::CREDIT_PROXY_URL is the shared single source of truth for the
  proxy origin (the browser app references it instead of duplicating).