fix: full-stack E2E hardening — client blobs, modal errors, audit coverage, MCP context

- api-client: getResponseBody returns Blob for non-JSON (fixes storage
  preview/download TypeError); postgen.mjs reapplies the patch on regen
- Modal: error prop renders inside the dialog so request failures are
  visible instead of hidden behind the overlay (6 pages wired)
- lib/api: extract server-provided error message from error.body
- Modal: unique id per instance (duplicate modal-title broke aria-label)
- nginx: index.html no-cache + immutable /assets (stale shell pointed at
  deleted hashed assets after redeploy → white screen)
- vite: drop dead Google Fonts runtime caching (fonts are vendored)
- functions: audit function.created/updated/deleted/invoked
- AuditPage: expand action filter to all recorded actions
- MCP: whoami uses /context for API keys; projectId/orgId resolve via
  /context with auth-aware precedence (stale `primora use` selection can
  never authorize a differently-scoped key)

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

apps/frontend/src/App.tsx

@@ -26,7 +26,7 @@ import {
 import { Show, createEffect, createMemo, createResource, createSignal, onCleanup } from "solid-js";
 
 import { authClient, fetchApiToken } from "./lib/auth-client";
-import { configureApiToken } from "./lib/api";
+import { configureApiToken, errorMessage } from "./lib/api";
 import { isDemoMode, disableDemoMode, enableDemoMode, demoSession, demoService } from "./lib/demo-mode";
 import {
   AppShell,
@@ -84,11 +84,7 @@ type ObjectPreview =
   | { kind: "unsupported"; message: string };
 
 function getErrorMessage(error: unknown, fallback: string) {
-  if (error && typeof error === "object" && "message" in error) {
-    const message = (error as { message?: unknown }).message;
-    if (typeof message === "string" && message.length > 0) return message;
-  }
-  return fallback;
+  return errorMessage(error, fallback);
 }
 
 function formatDate(value?: string | null) {