v5.6.2

P0 hotfix: restores search / query / store_put in local mode through the
T3 daemon (broken on 5.6.0 and 5.6.1).

Fixed

• Local-mode daemon embedding (P0, #1065). In local mode the T3 daemon
  (chroma run via HttpClient) has no registration for nexus's nexus_local
  embedding function, so any op relying on the collection's server-side EF fell
  back to ChromaDB's 384-dim DefaultEmbeddingFunction against 768-dim bge
  collections. Every search/query returned "No results" (dimension mismatch
  → all collections silently skipped) and store_put failed with
  "expecting 768 got 384". nexus now embeds client-side for every
  daemon-routed text op through a single _maybe_client_embed() chokepoint:
  searches send query_embeddings, writes send embeddings=. Cloud mode
  (server-side Voyage) and the CCE path are unchanged.
• Silent total-outage (#1065). search now logs an ERROR
  (search_all_collections_dimension_skipped) when every queried collection is
  dimension-skipped, instead of a silent empty result.
• Collection-model display (#1065). collection_list parses the 4-segment
  conformant name first, so bge collections no longer mislabel as
  voyage-code-3 / voyage-context-3; legacy 2-segment names still fall back.