v0.4.0

Everything about running the assistant used to mean editing backend/.env and
restarting: the provider, the key, which model does what, and — if you ever
changed the embedding model — the search index went stale until you found the
per-project reindex button yourself. This release moves all of that into the
app, and gives the sidebar and the entity list an overhaul that had been
overdue since projects stopped being the only thing in the rail.

Added

• AI settings in the app. A new page in the left rail (/settings) sets the
  provider, the API key, one model per task class (assistant / extraction /
  generation), the agent's token budget, and the embedding provider and model —
  without editing .env and without a restart. A model change applies to the
  next request; a running generation finishes on the model it started with.
  Each field says where its value came from (.env or set here) and can be
  reset back to the file, so "I edited .env and nothing happened" has an
  answer on screen.

• Test before you rely on it. A "Test" button makes one tiny call with the
  configuration currently in the form — a wrong key, a mistyped model id or an
  Ollama that isn't running now surfaces here instead of mid-generation. The
  embedding test also reports the model's dimensions.

• Model suggestions from the provider. Where a provider publishes a model
  list (OpenAI-compatible APIs, Anthropic, Ollama), the model fields suggest
  what is actually available; the field stays free text either way.

• Automatic reindex after an embedding change. Vectors from two different
  models are not comparable, so switching models now rebuilds every project's
  search data by itself — entities from SQLite, knowledge-base documents from
  their stored files — with progress on the settings page. It used to be a
  silent loss of retrieval until you found the per-project reindex button.

• A sidebar that is never empty. On the project list the rail used to hold
  a logo and three buttons; it now offers your recent projects, and inside a
  project it shows that project's sections. The two are labelled zones —
  Project above, App below — separated from each other.

• Search (Ctrl/⌘ K). Jump to an entity in the open project, or to any
  project by name, without walking the navigation.

• The assistant's state is visible from anywhere. A line at the bottom of
  the rail names the model that answers, warns when no API key is set, and
  shows a reindex while it runs. Previously a missing key surfaced only when
  you opened the assistant.

• Continue where you left off. The project list leads with the world you
  had open last, and gains a filter once you have more than a handful.

• The entity list groups itself by your relationships. A faction that
  contains its people — or whose people are member_of it — is now a folder
  you can fold, with its members nested inside; a town holds the places
  located_in it, however deep the nesting goes. Search still finds a member
  inside a folded folder and opens the way to it, and an entity that belongs to
  two factions is shown in both, marked as such rather than duplicated by
  accident. Two other arrangements are one click away — by type and the old
  flat list — and the choice is remembered per project. Dragging a row onto
  another row creates the containment relationship for real (with an undo in
  the toast), so the list is a way to edit the graph, not a second place where
  structure lives. Which relationship types count as "inside" is yours to set:
  Project settings → Grouping lists the types your world actually uses.

Changed

• No more two "Settings". The project's own settings are now called
  Project settings and stay in the project zone; the installation's are
  simply Settings at the bottom of the rail.
• Appearance is a settings section, not a popover. Theme, accent, language
  and updates each got their own place — the settings page is now tabbed
  (Models · Embeddings · Appearance · Updates · Tracing · Startup), with theme
  previews you can see before choosing. The one control frequent enough to
  stay in the rail is the light/dark/system switch.
• Collapse is a chevron on the rail's edge, not an item in the navigation
  list that looked like a fourth place you could go.
• backend/.env is now the bootstrap path rather than the only one: it is read
  at startup, and a value set in the UI overrides it. The first-run launcher
  wizard says so when you skip it, and the Assistant's setup card links to the
  settings page instead of printing .env snippets.
• GET /api/agent/config also reports which model backs each tier.

Migration

Automatic. A new app_settings table is created on first start; installations
that never open the settings page keep running exactly on their .env.