add setup onboarding page, dashboard launch checklist, provider registry

- new /setup page with three-section onboarding (account, provider, payments)
- dashboard launch checklist with progress bar, go-live, dismiss
- provider registry on Provider module (single source of truth for metadata)
- payments registry for Stripe
- setup context made provider-agnostic (provider_connected, theme_customised, etc.)
- admin provider pages now fully registry-driven (no hardcoded provider names)
- auth flow: fresh installs redirect to /setup, signed_in_path respects setup state
- removed old /admin/setup wizard
- 840 tests, 0 failures

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

lib/berrypod_web/live/admin/providers/form.html.heex

@@ -1,75 +1,32 @@
 <.header>
   {if @live_action == :new,
-    do: "Connect to #{provider_label(@provider_type)}",
-    else: "#{provider_label(@provider_type)} settings"}
+    do: "Connect to #{@provider.name}",
+    else: "#{@provider.name} settings"}
 </.header>
 
 <div class="max-w-xl mt-6">
   <%= if @live_action == :new do %>
     <div class="prose prose-sm mb-6">
       <p>
-        {provider_label(@provider_type)} is a print-on-demand service that prints and ships products for you.
+        {@provider.name} is a print-on-demand service that prints and ships products for you.
         Connect your account to automatically import your products into your shop.
       </p>
     </div>
 
-    <%= if @provider_type == "printify" do %>
-      <div class="rounded-lg bg-base-200 p-4 mb-6 text-sm">
-        <p class="font-medium mb-2">Get your API key from Printify:</p>
-        <ol class="list-decimal list-inside space-y-1 text-base-content/80">
-          <li>
-            <a
-              href="https://printify.com/app/auth/login"
-              target="_blank"
-              rel="noopener"
-              class="admin-link"
-            >
-              Log in to Printify
-            </a>
-            (or <a
-              href="https://printify.com/app/auth/register"
-              target="_blank"
-              rel="noopener"
-              class="admin-link"
-            >create a free account</a>)
-          </li>
-          <li>Click <strong>Account</strong> (top right)</li>
-          <li>Select <strong>Connections</strong> from the dropdown</li>
-          <li>Find <strong>API tokens</strong> and click <strong>Generate</strong></li>
-          <li>
-            Enter a name (e.g. "My Shop"), keep <strong>all scopes</strong>
-            selected, and click <strong>Generate token</strong>
-          </li>
-          <li>Click <strong>Copy to clipboard</strong> and paste it below</li>
-        </ol>
-      </div>
-    <% else %>
-      <div class="rounded-lg bg-base-200 p-4 mb-6 text-sm">
-        <p class="font-medium mb-2">Get your API key from Printful:</p>
-        <ol class="list-decimal list-inside space-y-1 text-base-content/80">
-          <li>
-            <a
-              href="https://www.printful.com/auth/login"
-              target="_blank"
-              rel="noopener"
-              class="admin-link"
-            >
-              Log in to Printful
-            </a>
-            (or <a
-              href="https://www.printful.com/auth/signup"
-              target="_blank"
-              rel="noopener"
-              class="admin-link"
-            >create a free account</a>)
-          </li>
-          <li>Go to <strong>Settings</strong> &rarr; <strong>API access</strong></li>
-          <li>Click <strong>Create API key</strong></li>
-          <li>Give it a name and select <strong>all scopes</strong></li>
-          <li>Copy the token and paste it below</li>
-        </ol>
-      </div>
-    <% end %>
+    <div class="rounded-lg bg-base-200 p-4 mb-6 text-sm">
+      <p class="font-medium mb-2">Get your API key from {@provider.name}:</p>
+      <ol class="list-decimal list-inside space-y-1 text-base-content/80">
+        <li>
+          <a href={@provider.login_url} target="_blank" rel="noopener" class="admin-link">
+            Log in to {@provider.name}
+          </a>
+          (or <a href={@provider.signup_url} target="_blank" rel="noopener" class="admin-link">create a free account</a>)
+        </li>
+        <li :for={step <- @provider.setup_steps}>
+          {raw(step)}
+        </li>
+      </ol>
+    </div>
   <% end %>
 
   <.form for={@form} id="provider-form" phx-change="validate" phx-submit="save">
@@ -78,7 +35,7 @@
     <.input
       field={@form[:api_key]}
       type="password"
-      label={"#{provider_label(@provider_type)} API key"}
+      label={"#{@provider.name} API key"}
       placeholder={
         if @live_action == :edit,
           do: "Leave blank to keep current key",
@@ -106,7 +63,7 @@
           <% {:ok, _info} -> %>
             <span class="text-success flex items-center gap-1">
               <.icon name="hero-check-circle" class="size-4" />
-              Connected to {connection_name(@test_result) || provider_label(@provider_type)}
+              Connected to {connection_name(@test_result) || @provider.name}
             </span>
           <% {:error, reason} -> %>
             <span class="text-error flex items-center gap-1">
@@ -124,7 +81,7 @@
     <div class="flex gap-2 mt-6">
       <.button type="submit" disabled={@testing}>
         {if @live_action == :new,
-          do: "Connect to #{provider_label(@provider_type)}",
+          do: "Connect to #{@provider.name}",
           else: "Save changes"}
       </.button>
       <.link navigate={~p"/admin/providers"} class="admin-btn admin-btn-ghost">