v0.55.0

Changed

• The agent runtime is django-spec-agents. The dependency on
  django-pydantic-agent>=0.28 becomes django-spec-agents>=0.1.0, the package
  that merges it with djangorestframework-pydantic-ai, and django-ag-ui is
  floored at 0.69.0, the release that runs on it; the two move together, because
  this package hands django-ag-ui the AgentDeps it builds. 0.1.0 carries
  django-pydantic-agent 0.28.2's host and its tests across under a new import
  root; django-ag-ui 0.69.0's changelog lists what a run can see change.
  A project that installs the reference store app changes its INSTALLED_APPS
  entry to "django_spec_agents.contrib.store" and runs migrate once, which
  renames the store's tables in place; it needs django-pydantic-agent's own store
  migrations applied first, which any project on 0.54 that has migrated already
  has. A project importing the old package
  directly moves those imports to django_spec_agents. A tool registered with
  @tool(registry, name="...") under a name other than its function's is now
  offered, gated and audited under that name, so a TOOL_GUARD entry naming it
  by its function name must use the registered name. The admin registers no
  such tool of its own.
• The [mcp] extra requires djangorestframework-mcp-server>=0.53.1, where
  a list selector raising Http404 through the bridge is a failed call reading
  not found rather than a successful empty list.
• Two tests hold the new floors where the lowest-declared-versions job resolves
  them: one drives a bridged list selector raising Http404, and one asserts
  neither replaced runtime is installed.