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, 49 insertions, 0 deletions

diff --git a/src/features/chat/model-select.test.ts b/src/features/chat/model-select.test.ts
index 33c1a16..57de11d 100644
--- a/src/features/chat/model-select.test.ts
+++ b/src/features/chat/model-select.test.ts
@@ -1,12 +1,18 @@
 import { describe, expect, it } from "vitest";
 import {
+  isNamedAgentSelection,
   isVisionModel,
   joinModelName,
   migrateLegacyModelName,
   modelKeyLabel,
   modelKeys,
   modelsForKey,
+  NAMED_AGENTS_PROVIDER,
+  namedAgentNames,
+  namedAgentSelectionLabel,
+  namedAgentsProviderLabel,
   openCodeNumber,
+  providerKeysWithNamedAgents,
   splitModelName,
 } from "./model-select";
 
@@ -143,3 +149,46 @@ describe("isVisionModel", () => {
     expect(isVisionModel({}, "kimi/k2")).toBe(false);
   });
 });
+
+describe("named-agent provider helpers", () => {
+  it("providerKeysWithNamedAgents puts the synthetic provider first, then raw keys", () => {
+    expect(providerKeysWithNamedAgents(["openai/gpt-4", "anthropic/claude"])).toEqual([
+      NAMED_AGENTS_PROVIDER,
+      "openai",
+      "anthropic",
+    ]);
+    // Always present even with zero models.
+    expect(providerKeysWithNamedAgents([])).toEqual([NAMED_AGENTS_PROVIDER]);
+  });
+
+  it("namedAgentsProviderLabel + NAMED_AGENTS_PROVIDER are stable", () => {
+    expect(namedAgentsProviderLabel()).toBe("Named Agents");
+    expect(NAMED_AGENTS_PROVIDER).toBe("__named_agents__");
+  });
+
+  it("namedAgentNames returns the display names", () => {
+    expect(namedAgentNames([{ id: "a", name: "Coding", model: "m" }])).toEqual(["Coding"]);
+  });
+
+  it("isNamedAgentSelection is true only for a snapshot whose model equals the selection", () => {
+    expect(
+      isNamedAgentSelection("opencode-1/claude", {
+        namedAgentId: "a",
+        namedAgentName: "C",
+        model: "opencode-1/claude",
+      }),
+    ).toBe(true);
+    expect(
+      isNamedAgentSelection("other/model", {
+        namedAgentId: "a",
+        namedAgentName: "C",
+        model: "opencode-1/claude",
+      }),
+    ).toBe(false);
+    expect(isNamedAgentSelection("opencode-1/claude", null)).toBe(false);
+  });
+
+  it("namedAgentSelectionLabel renders 'Named Agents -> <name>'", () => {
+    expect(namedAgentSelectionLabel("Coding")).toBe("Named Agents -> Coding");
+  });
+});