fix(honcho): read Honcho 3.0.x response schema — memory reads were silently empty

Against a self-hosted Honcho 3.0.11 every read path came back empty while
the server was healthy and full of derived facts: the plugin parsed a
`conclusions`/`summary` shape the API no longer emits.

- honcho-client: typed models for the real schema — `PeerContext`
  (`representation` markdown + `peer_card`), `SessionContext` (`summary` as
  an object, `peer_representation`), wrapped `PeerCard` (a bare array on PUT
  is a 422, which also broke `honcho_profile` writes).
- plugin: the turn-time injection and `honcho_context` read the
  representation; `honcho_search` and the page's /search now use
  `conclusions/query` (observer/observed scoping inside `filters`) — a real
  ranked semantic search with fact ids, which `peer_context?search_query`
  never provided; /overview returns card + representation + conclusions.
- compose: pin the Honcho image by digest (3.0.11) — ghcr publishes no v3
  semver tags, and an untracked `:latest` pull is what drifted the schema.
- tests: fixture tests from payloads captured on the live server, plus an
  env-gated live smoke test (HONCHO_E2E_URL/_WS/_PEER, `cargo test
  -p honcho-client -- --ignored`) — run it before any future Honcho bump.

docs/plugins/honcho.md

@@ -33,7 +33,7 @@ Long-term memory is **off for every user until they turn it on themselves**. Onc
 Once a user has opted in, that same page shows a **debug panel** over their own memory — useful to check the integration is working, and to see (and question) what has been derived:
 
 - **Service status** — whether the Honcho server is reachable (with the response time), how the user's own memory processing is doing (units in progress / pending / completed), and *the specific error* when something is wrong (server down, key rejected, server-side error), not just "unavailable".
-- **Overview** — everything Honcho has derived so far: the user's "card" (curated key facts), the individual facts (each with its id), and a summary. Loads automatically; nothing to type.
+- **Overview** — everything Honcho has derived so far: the user's "card" (curated key facts — empty until some are set, e.g. via the `honcho_profile` tool), the individual facts (each with its id), and the full **representation** digest Honcho hands to the assistant on every turn. Loads automatically; nothing to type.
 - **Search or ask** — one text field, two actions, with a mini-guide on the page:
   - **Search** finds the stored facts most relevant to the words typed — fast, exact, raw facts.
   - **Ask** sends the question to Honcho's AI, which reads the user's memory and writes an answer in its own words — slower, but it connects the dots.