feat: Cloudflare Turnstile on auth, CSP fixes, admin/SEO/analytics additions

Turnstile bot protection (sign-in, sign-up, password-reset):
- Register Better Auth's captcha plugin with the cloudflare-turnstile
  provider; endpoints listed explicitly rather than relying on defaults.
  /reset-password is intentionally excluded — it is reached only via a
  single-use emailed token.
- Add an explicit-render Turnstile widget component. Tokens are single-use,
  so each form resets the challenge after a failed submit; submit stays
  disabled until a token is held.
- Read the site key server-side and pass it down as a prop, so rotating it
  does not require a rebuild.
- Fail fast in production when TURNSTILE_SECRET_KEY is missing, and when a
  secret is set without a site key (that combination would demand a token
  no form can produce, locking every user out).
- Pass a throwaway secret during `next build` in the Dockerfile, mirroring
  the existing BETTER_AUTH_SECRET treatment, so image builds don't need it.

CSP fixes in middleware (these blocked Turnstile entirely):
- Add frame-src for challenges.cloudflare.com. Without it the widget's
  iframe fell back to default-src 'self' and was blocked outright.
- Allow 'unsafe-eval' and websockets in DEVELOPMENT only. `next dev`
  compiles with eval(), so the strict policy threw EvalError and killed
  hydration — no client JS ran at all, which also meant form submit
  handlers never fired. Production policy is unchanged and still strict.

Also included (concurrent work in the tree):
- Admin organizations pages and lib/admin/orgs.
- Episode moderation migration, SEO metadata (sitemap, robots, JSON-LD,
  OG/Twitter images, manifest), Umami analytics, not-found page.

Local dev database: docker-compose.dev.yml provisions Postgres 18 on port
5443 (5432-5442 are in use by other local projects).

Note: `npx tsc --noEmit` currently fails in app/(app)/team/page.tsx — an
`invitations` prop the component does not accept. This predates the commit
and will fail `next build` until fixed.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

lib/schema.ts

@@ -0,0 +1,143 @@
+import { PLANS, PLAN_ORDER } from "@/lib/billing/plans";
+import { SITE_DESCRIPTION, SITE_NAME, SITE_URL, absoluteUrl } from "@/lib/seo";
+
+/**
+ * schema.org JSON-LD builders.
+ *
+ * Everything is emitted into a single `@graph` per page with stable `@id`s, so
+ * nodes can reference each other (e.g. the software product is `publisher`-ed by
+ * the organization) instead of being repeated on every route.
+ */
+
+const ORG_ID = `${SITE_URL}/#organization`;
+const SITE_ID = `${SITE_URL}/#website`;
+const APP_ID = `${SITE_URL}/#software`;
+
+export function organizationSchema() {
+  return {
+    "@type": "Organization",
+    "@id": ORG_ID,
+    name: SITE_NAME,
+    url: absoluteUrl("/"),
+    description: SITE_DESCRIPTION,
+    logo: {
+      "@type": "ImageObject",
+      url: absoluteUrl("/logo-dark.png"),
+      contentUrl: absoluteUrl("/logo-dark.png"),
+    },
+    contactPoint: [
+      {
+        "@type": "ContactPoint",
+        contactType: "customer support",
+        email: "support@podcastdistributionai.com",
+        availableLanguage: ["English"],
+      },
+    ],
+  };
+}
+
+export function websiteSchema() {
+  return {
+    "@type": "WebSite",
+    "@id": SITE_ID,
+    url: absoluteUrl("/"),
+    name: SITE_NAME,
+    description: SITE_DESCRIPTION,
+    publisher: { "@id": ORG_ID },
+    inLanguage: "en",
+  };
+}
+
+/**
+ * The product itself, with one Offer per plan. Prices come from the plan catalog
+ * so the markup can never drift from what the pricing page actually charges.
+ */
+export function softwareApplicationSchema() {
+  return {
+    "@type": "SoftwareApplication",
+    "@id": APP_ID,
+    name: SITE_NAME,
+    url: absoluteUrl("/"),
+    description: SITE_DESCRIPTION,
+    applicationCategory: "MultimediaApplication",
+    applicationSubCategory: "Podcast production",
+    operatingSystem: "Web browser",
+    publisher: { "@id": ORG_ID },
+    featureList: [
+      "AI podcast script generation",
+      "Realistic multi-voice text-to-speech",
+      "AI-generated episode cover art",
+      "Content repurposing to blog and social posts",
+      "Series and season generator",
+      "13+ languages",
+      "Team workspace and white-label branding",
+      "REST API access",
+    ],
+    offers: PLAN_ORDER.map((key) => {
+      const plan = PLANS[key];
+      return {
+        "@type": "Offer",
+        name: `${plan.name} plan`,
+        description: plan.tagline,
+        price: (plan.priceMonthly / 100).toFixed(2),
+        priceCurrency: "USD",
+        category: plan.priceMonthly === 0 ? "Free" : "Subscription",
+        url: absoluteUrl("/pricing"),
+        availability: "https://schema.org/InStock",
+      };
+    }),
+  };
+}
+
+/** A single page node, linked to the site — gives each URL an explicit identity. */
+export function webPageSchema({
+  path,
+  name,
+  description,
+}: {
+  path: string;
+  name: string;
+  description: string;
+}) {
+  return {
+    "@type": "WebPage",
+    "@id": `${absoluteUrl(path)}#webpage`,
+    url: absoluteUrl(path),
+    name,
+    description,
+    isPartOf: { "@id": SITE_ID },
+    about: { "@id": ORG_ID },
+    inLanguage: "en",
+  };
+}
+
+/** Breadcrumbs from Home to the current page. Pass the trail without Home. */
+export function breadcrumbSchema(trail: { name: string; path: string }[]) {
+  return {
+    "@type": "BreadcrumbList",
+    "@id": `${absoluteUrl(trail[trail.length - 1]?.path ?? "/")}#breadcrumb`,
+    itemListElement: [{ name: "Home", path: "/" }, ...trail].map((item, i) => ({
+      "@type": "ListItem",
+      position: i + 1,
+      name: item.name,
+      item: absoluteUrl(item.path),
+    })),
+  };
+}
+
+export function faqPageSchema(items: { q: string; a: string }[]) {
+  return {
+    "@type": "FAQPage",
+    "@id": `${absoluteUrl("/faq")}#faq`,
+    mainEntity: items.map(({ q, a }) => ({
+      "@type": "Question",
+      name: q,
+      acceptedAnswer: { "@type": "Answer", text: a },
+    })),
+  };
+}
+
+/** Wrap nodes into the `@graph` envelope every page emits. */
+export function graph(...nodes: Record<string, unknown>[]) {
+  return { "@context": "https://schema.org", "@graph": nodes };
+}