feat: complete release readiness work

- consolidate API ownership and remove dead vendor code

- add Stripe billing, learning paths, and public CV hardening

- add migration, recovery, security, audit, and browser gates

job-tracker-ui/src/applicationWorkspace.test.ts

@@ -0,0 +1,8 @@
+import { WORKSPACE_SECTIONS, workspaceSection } from "./applicationWorkspace";
+
+test("workspace navigation rejects removed and unknown sections", () => {
+  expect(WORKSPACE_SECTIONS.map((section) => section.key)).not.toContain("portfolio");
+  expect(WORKSPACE_SECTIONS.map((section) => section.key)).not.toContain("notes");
+  expect(workspaceSection("match")).toBe("match");
+  expect(workspaceSection("portfolio")).toBe("overview");
+});