feat(cli): add --model/--provider flags and /model /provider TUI commands (#144)

Co-authored-by: Jason Woltje <jason@diversecanvas.com>
Co-committed-by: Jason Woltje <jason@diversecanvas.com>

packages/cli/src/tui/gateway-api.ts

@@ -0,0 +1,62 @@
+/**
+ * Minimal gateway REST API client for the TUI.
+ */
+
+export interface ModelInfo {
+  id: string;
+  provider: string;
+  name: string;
+}
+
+export interface ProviderInfo {
+  id: string;
+  name: string;
+  available: boolean;
+  models: ModelInfo[];
+}
+
+/**
+ * Fetch the list of available models from the gateway.
+ * Returns an empty array on network or auth errors so the TUI can still function.
+ */
+export async function fetchAvailableModels(
+  gatewayUrl: string,
+  sessionCookie?: string,
+): Promise<ModelInfo[]> {
+  try {
+    const res = await fetch(`${gatewayUrl}/api/providers/models`, {
+      headers: {
+        ...(sessionCookie ? { Cookie: sessionCookie } : {}),
+        Origin: gatewayUrl,
+      },
+    });
+    if (!res.ok) return [];
+    const data = (await res.json()) as ModelInfo[];
+    return Array.isArray(data) ? data : [];
+  } catch {
+    return [];
+  }
+}
+
+/**
+ * Fetch the list of providers (with their models) from the gateway.
+ * Returns an empty array on network or auth errors.
+ */
+export async function fetchProviders(
+  gatewayUrl: string,
+  sessionCookie?: string,
+): Promise<ProviderInfo[]> {
+  try {
+    const res = await fetch(`${gatewayUrl}/api/providers`, {
+      headers: {
+        ...(sessionCookie ? { Cookie: sessionCookie } : {}),
+        Origin: gatewayUrl,
+      },
+    });
+    if (!res.ok) return [];
+    const data = (await res.json()) as ProviderInfo[];
+    return Array.isArray(data) ? data : [];
+  } catch {
+    return [];
+  }
+}