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>

app/(app)/team/actions.ts

@@ -93,6 +93,107 @@ export async function inviteMemberAction(
   return { ok: true };
 }
 
+/**
+ * Shared authorization for every workspace mutation: the caller must be an
+ * owner/admin of THIS organization. Returns the caller's role, or an error.
+ */
+async function requireOrgAdmin(
+  organizationId: string
+): Promise<{ ok: true; userId: string; role: string } | { ok: false; error: string }> {
+  const session = await getServerSession();
+  if (!session) return { ok: false, error: "You must be signed in." };
+  const member = await prisma.member.findFirst({
+    where: { organizationId, userId: session.user.id },
+    select: { role: true },
+  });
+  if (!member || !["owner", "admin"].includes(member.role)) {
+    return { ok: false, error: "Only workspace owners can manage members." };
+  }
+  return { ok: true, userId: session.user.id, role: member.role };
+}
+
+/**
+ * Remove a member, freeing their seat.
+ *
+ * Guards: only owner/admin may remove; nobody may remove themselves (that would
+ * orphan the workspace from the UI); and the last remaining owner is protected,
+ * otherwise a workspace can be left with no one able to administer it.
+ */
+export async function removeMemberAction(
+  organizationId: string,
+  memberId: string
+): Promise<{ ok: boolean; error?: string }> {
+  const auth = await requireOrgAdmin(organizationId);
+  if (!auth.ok) return { ok: false, error: auth.error };
+
+  const target = await prisma.member.findFirst({
+    where: { id: memberId, organizationId },
+    select: { id: true, userId: true, role: true },
+  });
+  if (!target) return { ok: false, error: "Member not found." };
+  if (target.userId === auth.userId) {
+    return { ok: false, error: "You can't remove yourself from the workspace." };
+  }
+  if (target.role === "owner") {
+    const owners = await prisma.member.count({ where: { organizationId, role: "owner" } });
+    if (owners <= 1) return { ok: false, error: "The workspace must keep at least one owner." };
+  }
+
+  await prisma.member.delete({ where: { id: target.id } });
+  revalidatePath("/team");
+  return { ok: true };
+}
+
+/** Change a member's workspace role. Same last-owner protection as removal. */
+export async function updateMemberRoleAction(
+  organizationId: string,
+  memberId: string,
+  role: "owner" | "admin" | "member"
+): Promise<{ ok: boolean; error?: string }> {
+  const auth = await requireOrgAdmin(organizationId);
+  if (!auth.ok) return { ok: false, error: auth.error };
+
+  // `role` is client-supplied and only TS-typed — validate it at runtime.
+  const parsedRole = z.enum(["owner", "admin", "member"]).safeParse(role);
+  if (!parsedRole.success) return { ok: false, error: "Invalid role." };
+
+  const target = await prisma.member.findFirst({
+    where: { id: memberId, organizationId },
+    select: { id: true, userId: true, role: true },
+  });
+  if (!target) return { ok: false, error: "Member not found." };
+  if (target.role === "owner" && parsedRole.data !== "owner") {
+    const owners = await prisma.member.count({ where: { organizationId, role: "owner" } });
+    if (owners <= 1) return { ok: false, error: "The workspace must keep at least one owner." };
+  }
+
+  await prisma.member.update({ where: { id: target.id }, data: { role: parsedRole.data } });
+  revalidatePath("/team");
+  return { ok: true };
+}
+
+/**
+ * Revoke a pending invitation, freeing the seat it was holding.
+ * Scoped to the organization so an id from another workspace can't be cancelled.
+ */
+export async function revokeInvitationAction(
+  organizationId: string,
+  invitationId: string
+): Promise<{ ok: boolean; error?: string }> {
+  const auth = await requireOrgAdmin(organizationId);
+  if (!auth.ok) return { ok: false, error: auth.error };
+
+  const invite = await prisma.invitation.findFirst({
+    where: { id: invitationId, organizationId, status: "pending" },
+    select: { id: true },
+  });
+  if (!invite) return { ok: false, error: "Invitation not found." };
+
+  await prisma.invitation.update({ where: { id: invite.id }, data: { status: "canceled" } });
+  revalidatePath("/team");
+  return { ok: true };
+}
+
 export async function saveBrandingAction(
   organizationId: string,
   data: z.infer<typeof brandingSchema>

app/(app)/team/page.tsx

@@ -43,7 +43,31 @@ export default async function TeamPage() {
   });
   const org = membership?.organization ?? null;
   const members =
-    org?.members.map((m) => ({ id: m.id, name: m.user.name, email: m.user.email, role: m.role })) ?? [];
+    org?.members.map((m) => ({
+      id: m.id,
+      userId: m.userId,
+      name: m.user.name,
+      email: m.user.email,
+      role: m.role,
+    })) ?? [];
+
+  // Pending invitations hold a seat until accepted or revoked, so they belong on
+  // this screen next to members — otherwise a workspace can look under-capacity
+  // while every seat is actually spoken for.
+  const invitations = org
+    ? (
+        await prisma.invitation.findMany({
+          where: { organizationId: org.id, status: "pending" },
+          orderBy: { expiresAt: "desc" },
+          select: { id: true, email: true, role: true, expiresAt: true },
+        })
+      ).map((i) => ({
+        id: i.id,
+        email: i.email,
+        role: i.role ?? "member",
+        expiresAt: i.expiresAt.toISOString(),
+      }))
+    : [];
 
   return (
     <>
@@ -51,6 +75,8 @@ export default async function TeamPage() {
       <TeamClient
         org={org ? { id: org.id, name: org.name } : null}
         members={members}
+        invitations={invitations}
+        currentUserId={session.user.id}
         branding={
           org?.branding
             ? {