feat(named-agents): sidebar view, synthetic provider, auto-save, snapshot semantics

Implement the frontend of the Named Agents feature (plan §5-§9):
- New features/named-agents module: pure logic (types re-exported from
  @dispatch/wire + transport-contract, validation, provider/model options,
  snapshot helpers, network normalizers, auto-save status model) + an injected
  auto-save controller (name debounce, immediate provider/model save, monotonic
  stale-response guard) + the collapsible sidebar card view.
- Store: /named-agents CRUD + boot seed; selectModel(model, snapshot?) persists
  the raw model WITH the namedAgent snapshot; draft promotion carries it;
  refreshModel restores ModelResponse.namedAgent.
- Chat store setNamedAgent (sends namedAgent on chat.send); Tab.snapshot +
  setSnapshot (retained across rename/remove, persisted with tabs).
- Model selector: synthetic Named Agents provider ALWAYS first; selecting one
  resolves to the raw model + records a snapshot; a retained snapshot of a
  renamed/removed agent still displays as unavailable (plan §7).
- Composition root wires the view (viewKinds + loaded-modules manifest) + feeds
  the selector.

Tests: logic + controller + selector + app-store CRUD (1246 pass), typecheck 0,
biome clean (only pre-existing config infos pending a future migrate), build OK.

1 files changed, 47 insertions, 0 deletions

diff --git a/src/features/named-agents/logic/validate.ts b/src/features/named-agents/logic/validate.ts
new file mode 100644
index 0000000..c25524a
--- /dev/null
+++ b/src/features/named-agents/logic/validate.ts
@@ -0,0 +1,47 @@
+/**
+ * Pure validation for Named Agent form fields — zero DOM, zero effects.
+ *
+ * A Named Agent is usable only when (plan §5.4): the name is nonempty + unique
+ * case-insensitively, and a provider + model are selected. These pure helpers
+ * drive the card UI's validity gating + inline messages; the backend remains
+ * the authority (it 400s/conflicts on a duplicate or empty name / malformed
+ * model identifier).
+ */
+
+/** Trim + collapse runs of whitespace inside a name (survey-style display). */
+export function normalizeName(raw: string): string {
+  return raw.trim().replace(/\s+/g, " ");
+}
+
+/**
+ * A name-validation error message, or `null` when the name is valid. `otherNames`
+ * are the OTHER agents' names for the case-insensitive uniqueness check (the
+ * caller EXCLUDES the card's own last-persisted name / the card being edited).
+ */
+export function nameError(name: string, otherNames: readonly string[]): string | null {
+  const normalized = normalizeName(name);
+  if (normalized.length === 0) return "Name is required.";
+  const lower = normalized.toLowerCase();
+  for (const other of otherNames) {
+    if (other.trim().toLowerCase() === lower) return "A named agent with this name already exists.";
+  }
+  return null;
+}
+
+/** True iff `name` is a unique, nonempty agent name among `otherNames`. */
+export function isUsableName(name: string, otherNames: readonly string[]): boolean {
+  return nameError(name, otherNames) === null;
+}
+
+/**
+ * Whether a full model identifier is syntactically valid — a canonical
+ * `<provider>/<model>` with a nonempty provider (the part before the first "/")
+ * AND a nonempty model (the part after). A slashless or provider-only value is
+ * invalid for a Named Agent (it must resolve to a concrete model).
+ */
+export function isUsableModel(full: string): boolean {
+  const i = full.indexOf("/");
+  if (i <= 0) return false; // no slash, or empty provider
+  const model = full.slice(i + 1);
+  return model.length > 0;
+}