v0.41.0-beta.3

• Git / CI: one integration branch (develop) plus stable v* tags. Staging
  follows develop; production and live docs follow a tagged release. master
  is no longer a deploy or docs trigger, and main is not introduced as a
  copy of the latest tag.
• Fix: Atomic Canvas no longer returns to the gallery when the screen rotates.
  Android was treating the rotation as a back press.
• Fix: built-in defaults (lib/defaults/*.json + base models) now reach
  existing stores. The store records a fingerprint of the embedded defaults;
  every open (server and browser/OPFS) re-seeds add-only when the fingerprint
  changed, so a Property or Class added in a new release no longer 404s against
  a store seeded by an older one. Existing values, including user edits to
  default resources, are never overwritten. --repopulate-defaults remains as
  a forced re-run with the same add-only semantics.
• atomic_lib: atomic_lib::runtime::AtomicNode — a named node surface over
  Db (open, get, query, apply_commit(json, IngestPolicy), mutate,
  subscribe, sync_with_peer). Thin delegation, no behaviour change; the
  WASM ClientDb is the first adapter on it. IngestPolicy::{Hub, Peer, Replica, LocalCache} names the four commit-validation profiles.
  sync::engine::ingest_commit returns the CommitResponse that
  ingest_commit_json serializes; sync::ws_apply::apply_commit_json now
  returns the CommitResponse instead of (). See
  planning/runtime-boundary-decision.md.