feat(navigation): add external entry routing

src/lib/navigation/__tests__/external_entry.test.ts

@@ -0,0 +1,47 @@
+import { describe, expect, it } from "vitest";
+
+import { ROUTES } from "@/router/routes";
+
+import { resolveExternalEntryTarget } from "../external_entry";
+
+describe("external entry navigation", () => {
+  it("defaults to chat", () => {
+    expect(resolveExternalEntryTarget({})).toBe(ROUTES.chat);
+  });
+
+  it("resolves supported target aliases", () => {
+    expect(resolveExternalEntryTarget({ target: "chat" })).toBe(ROUTES.chat);
+    expect(resolveExternalEntryTarget({ target: "tip" })).toBe(ROUTES.tip);
+    expect(resolveExternalEntryTarget({ target: "coffee" })).toBe(ROUTES.tip);
+    expect(resolveExternalEntryTarget({ target: "private-room" })).toBe(
+      ROUTES.privateRoom,
+    );
+    expect(resolveExternalEntryTarget({ target: "private_room" })).toBe(
+      ROUTES.privateRoom,
+    );
+  });
+
+  it("prefers safe explicit redirect routes over target aliases", () => {
+    expect(
+      resolveExternalEntryTarget({
+        target: "chat",
+        redirect: ROUTES.tip,
+      }),
+    ).toBe(ROUTES.tip);
+  });
+
+  it("rejects unsupported and external redirect routes", () => {
+    expect(
+      resolveExternalEntryTarget({
+        redirect: "https://example.com/chat",
+        target: "unknown",
+      }),
+    ).toBe(ROUTES.chat);
+    expect(resolveExternalEntryTarget({ redirect: "//example.com" })).toBe(
+      ROUTES.chat,
+    );
+    expect(resolveExternalEntryTarget({ redirect: "/sidebar" })).toBe(
+      ROUTES.chat,
+    );
+  });
+});