feat(ai): self-host settings UI for Anthropic provider (5/5)

Adds the Anthropic panel and the install-wide LLM provider selector to
the self-hosting settings page, plus a shared data-retention
disclosure that covers both OpenAI and Anthropic.

- New _llm_provider_selector partial: select for Setting.llm_provider
  (openai | anthropic), respects the LLM_PROVIDER env var (disables the
  control + shows the "configured through environment variables" hint
  when set, mirroring the existing OpenAI panel behaviour), and renders
  a compact data-handling block with one-line retention statements for
  each provider.
- New _anthropic_settings partial mirrors _openai_settings exactly:
  password-field for the API key with **** redaction, optional
  base_url (for AWS Bedrock / GCP Vertex), optional default model. All
  three fields disable when their ENV var is set.
- show.html.erb renders provider selector + OpenAI panel + Anthropic
  panel under the same "General" section so users can configure either
  (or both) without switching pages.
- Settings::HostingsController#update now permits and persists
  anthropic_access_token (ignoring the **** placeholder, same pattern
  as OpenAI), anthropic_base_url, anthropic_model, and llm_provider
  (validated against %w[openai anthropic]). On Setting::ValidationError
  the rescue branch preserves anthropic_base_url / anthropic_model
  input so the form re-renders with the user's typed values intact —
  parity with the issue #1824 fix for OpenAI.
- Locale keys added under settings.hostings.{llm_provider_selector,
  anthropic_settings}.

Tests cover token update + placeholder redaction, base_url + model
update, llm_provider switch to anthropic, and rejection of unknown
provider values. The existing GET render test still passes, exercising
all three new partials.

Closes the 5/5 Anthropic series stacked on #1986.

app/controllers/settings/hostings_controller.rb

@@ -166,6 +166,28 @@ class Settings::HostingsController < ApplicationController
       Setting.openai_json_mode = hosting_params[:openai_json_mode].presence
     end
 
+    if hosting_params.key?(:anthropic_access_token)
+      token_param = hosting_params[:anthropic_access_token].to_s.strip
+      unless token_param.blank? || token_param == "********"
+        Setting.anthropic_access_token = token_param
+      end
+    end
+
+    if hosting_params.key?(:anthropic_base_url)
+      Setting.anthropic_base_url = hosting_params[:anthropic_base_url].presence
+    end
+
+    if hosting_params.key?(:anthropic_model)
+      Setting.anthropic_model = hosting_params[:anthropic_model].presence
+    end
+
+    if hosting_params.key?(:llm_provider)
+      provider = hosting_params[:llm_provider].to_s
+      if %w[openai anthropic].include?(provider)
+        Setting.llm_provider = provider
+      end
+    end
+
     LLM_BUDGET_MINIMUMS.each do |key, minimum|
       next unless hosting_params.key?(key)
       raw = hosting_params[key].to_s.strip
@@ -206,6 +228,8 @@ class Settings::HostingsController < ApplicationController
     # be wiped because the view reads from the unchanged Setting.* values.
     @openai_uri_base_input = hosting_params[:openai_uri_base] if hosting_params.key?(:openai_uri_base)
     @openai_model_input = hosting_params[:openai_model] if hosting_params.key?(:openai_model)
+    @anthropic_base_url_input = hosting_params[:anthropic_base_url] if hosting_params.key?(:anthropic_base_url)
+    @anthropic_model_input = hosting_params[:anthropic_model] if hosting_params.key?(:anthropic_model)
     flash.now[:alert] = error.message
     render :show, status: :unprocessable_entity
   end
@@ -229,7 +253,7 @@ class Settings::HostingsController < ApplicationController
   private
     def hosting_params
       return ActionController::Parameters.new unless params.key?(:setting)
-      params.require(:setting).permit(:onboarding_state, :require_email_confirmation, :invite_only_default_family_id, :brand_fetch_client_id, :brand_fetch_high_res_logos, :twelve_data_api_key, :tiingo_api_key, :eodhd_api_key, :alpha_vantage_api_key, :openai_access_token, :openai_uri_base, :openai_model, :openai_json_mode, :llm_context_window, :llm_max_response_tokens, :llm_max_items_per_call, :exchange_rate_provider, :securities_provider, :syncs_include_pending, :auto_sync_enabled, :auto_sync_time, :external_assistant_url, :external_assistant_token, :external_assistant_agent_id, securities_providers: [])
+      params.require(:setting).permit(:onboarding_state, :require_email_confirmation, :invite_only_default_family_id, :brand_fetch_client_id, :brand_fetch_high_res_logos, :twelve_data_api_key, :tiingo_api_key, :eodhd_api_key, :alpha_vantage_api_key, :openai_access_token, :openai_uri_base, :openai_model, :openai_json_mode, :anthropic_access_token, :anthropic_base_url, :anthropic_model, :llm_provider, :llm_context_window, :llm_max_response_tokens, :llm_max_items_per_call, :exchange_rate_provider, :securities_provider, :syncs_include_pending, :auto_sync_enabled, :auto_sync_time, :external_assistant_url, :external_assistant_token, :external_assistant_agent_id, securities_providers: [])
     end
 
     def update_assistant_type

app/views/settings/hostings/_anthropic_settings.html.erb

@@ -0,0 +1,53 @@
+<div class="space-y-4">
+  <div>
+    <h2 class="font-medium mb-1"><%= t(".title") %></h2>
+    <% if ENV["ANTHROPIC_ACCESS_TOKEN"].present? || ENV["ANTHROPIC_API_KEY"].present? %>
+      <p class="text-sm text-secondary"><%= t(".env_configured_message") %></p>
+    <% else %>
+      <p class="text-secondary text-sm mb-4"><%= t(".description") %></p>
+    <% end %>
+  </div>
+
+  <%= styled_form_with model: Setting.new,
+                       url: settings_hosting_path,
+                       method: :patch,
+                       class: "space-y-4",
+                       data: {
+                         controller: "auto-submit-form",
+                         "auto-submit-form-trigger-event-value": "blur"
+                       } do |form| %>
+    <%= form.password_field :anthropic_access_token,
+                            label: t(".access_token_label"),
+                            placeholder: t(".access_token_placeholder"),
+                            value: (Setting.anthropic_access_token.present? ? "********" : nil),
+                            autocomplete: "off",
+                            autocapitalize: "none",
+                            spellcheck: "false",
+                            inputmode: "text",
+                            disabled: ENV["ANTHROPIC_ACCESS_TOKEN"].present? || ENV["ANTHROPIC_API_KEY"].present?,
+                            data: { "auto-submit-form-target": "auto" } %>
+
+    <%= form.text_field :anthropic_base_url,
+                        label: t(".base_url_label"),
+                        placeholder: t(".base_url_placeholder"),
+                        value: @anthropic_base_url_input || Setting.anthropic_base_url,
+                        autocomplete: "off",
+                        autocapitalize: "none",
+                        spellcheck: "false",
+                        inputmode: "url",
+                        disabled: ENV["ANTHROPIC_BASE_URL"].present?,
+                        data: { "auto-submit-form-target": "auto" } %>
+
+    <%= form.text_field :anthropic_model,
+                        label: t(".model_label"),
+                        placeholder: t(".model_placeholder"),
+                        value: @anthropic_model_input || Setting.anthropic_model,
+                        autocomplete: "off",
+                        autocapitalize: "none",
+                        spellcheck: "false",
+                        inputmode: "text",
+                        disabled: ENV["ANTHROPIC_MODEL"].present?,
+                        data: { "auto-submit-form-target": "auto" } %>
+    <p class="text-xs text-secondary mt-1"><%= t(".model_help") %></p>
+  <% end %>
+</div>

app/views/settings/hostings/_llm_provider_selector.html.erb

@@ -0,0 +1,38 @@
+<div class="space-y-3">
+  <div>
+    <h2 class="font-medium mb-1"><%= t(".title") %></h2>
+    <% if ENV["LLM_PROVIDER"].present? %>
+      <p class="text-sm text-secondary"><%= t(".env_configured_message") %></p>
+    <% else %>
+      <p class="text-secondary text-sm"><%= t(".description") %></p>
+    <% end %>
+  </div>
+
+  <%= styled_form_with model: Setting.new,
+                       url: settings_hosting_path,
+                       method: :patch,
+                       class: "space-y-3",
+                       data: {
+                         controller: "auto-submit-form",
+                         "auto-submit-form-trigger-event-value": "change"
+                       } do |form| %>
+    <%= form.select :llm_provider,
+                    options_for_select(
+                      [
+                        [ t(".provider_openai"), "openai" ],
+                        [ t(".provider_anthropic"), "anthropic" ]
+                      ],
+                      Setting.llm_provider
+                    ),
+                    { label: t(".provider_label") },
+                    { disabled: ENV["LLM_PROVIDER"].present?,
+                      data: { "auto-submit-form-target": "auto" } } %>
+    <p class="text-xs text-secondary"><%= t(".provider_help") %></p>
+  <% end %>
+
+  <div class="rounded-md border border-secondary p-3 bg-surface-secondary text-xs text-secondary space-y-2">
+    <p class="font-medium text-primary"><%= t(".data_retention_heading") %></p>
+    <p><%= t(".data_retention_openai") %></p>
+    <p><%= t(".data_retention_anthropic") %></p>
+  </div>
+</div>

app/views/settings/hostings/show.html.erb

@@ -4,7 +4,9 @@
 <% end %>
 <%= settings_section title: t(".general") do %>
     <div class="space-y-6">
+    <%= render "settings/hostings/llm_provider_selector" %>
     <%= render "settings/hostings/openai_settings" %>
+    <%= render "settings/hostings/anthropic_settings" %>
     <%= render "settings/hostings/brand_fetch_settings" %>
   </div>
 <% end %>

config/locales/views/settings/hostings/en.yml

@@ -90,6 +90,28 @@ en:
         title: Brand Fetch Settings
         high_res_label: Enable high-resolution logos
         high_res_description: When enabled, logos will be retrieved at 120x120 resolution instead of 40x40. This provides sharper images on high-DPI displays.
+      llm_provider_selector:
+        title: AI Provider
+        description: Choose which LLM powers chat, transaction categorization, merchant detection, and PDF processing.
+        env_configured_message: Successfully configured through the LLM_PROVIDER environment variable.
+        provider_label: Active LLM provider
+        provider_openai: OpenAI
+        provider_anthropic: Anthropic (Claude)
+        provider_help: Switching providers takes effect on the next chat or batch operation. Make sure the chosen provider's credentials are configured below.
+        data_retention_heading: Data handling
+        data_retention_openai: "OpenAI: API inputs are not used to train models by default. Standard retention is 30 days for trust & safety."
+        data_retention_anthropic: "Anthropic: API inputs are not used to train models by default. Standard retention is 30 days for trust & safety."
+      anthropic_settings:
+        title: Anthropic (Claude)
+        description: Enter your Anthropic API key. Optionally point Base URL at AWS Bedrock or GCP Vertex.
+        env_configured_message: Successfully configured through environment variables.
+        access_token_label: API Key
+        access_token_placeholder: Enter your Anthropic API key
+        base_url_label: Base URL (Optional)
+        base_url_placeholder: "https://api.anthropic.com (default)"
+        model_label: Default Model (Optional)
+        model_placeholder: "claude-sonnet-4-6 (default)"
+        model_help: Used for chat and PDF processing. Batch operations (categorize, merchant detection) default to Haiku for cost.
       openai_settings:
         description: Enter the access token and optionally configure a custom OpenAI-compatible provider
         env_configured_message: Successfully configured through environment variables.

test/controllers/settings/hostings_controller_test.rb

@@ -74,6 +74,51 @@ class Settings::HostingsControllerTest < ActionDispatch::IntegrationTest
     end
   end
 
+  test "can update anthropic access token when self hosting is enabled" do
+    with_self_hosting do
+      patch settings_hosting_url, params: { setting: { anthropic_access_token: "sk-ant-test" } }
+
+      assert_equal "sk-ant-test", Setting.anthropic_access_token
+    end
+  end
+
+  test "ignores redacted anthropic token placeholder" do
+    with_self_hosting do
+      Setting.anthropic_access_token = "previous-token"
+
+      patch settings_hosting_url, params: { setting: { anthropic_access_token: "********" } }
+
+      assert_equal "previous-token", Setting.anthropic_access_token
+    end
+  end
+
+  test "can update anthropic base_url and model" do
+    with_self_hosting do
+      patch settings_hosting_url, params: { setting: { anthropic_base_url: "https://bedrock.example.com", anthropic_model: "claude-opus-4-7" } }
+
+      assert_equal "https://bedrock.example.com", Setting.anthropic_base_url
+      assert_equal "claude-opus-4-7", Setting.anthropic_model
+    end
+  end
+
+  test "can update llm_provider to anthropic" do
+    with_self_hosting do
+      patch settings_hosting_url, params: { setting: { llm_provider: "anthropic" } }
+
+      assert_equal "anthropic", Setting.llm_provider
+    end
+  end
+
+  test "rejects unknown llm_provider values" do
+    with_self_hosting do
+      Setting.llm_provider = "openai"
+
+      patch settings_hosting_url, params: { setting: { llm_provider: "bogus" } }
+
+      assert_equal "openai", Setting.llm_provider
+    end
+  end
+
   test "can update openai uri base and model together when self hosting is enabled" do
     with_self_hosting do
       patch settings_hosting_url, params: { setting: { openai_uri_base: "https://api.example.com/v1", openai_model: "gpt-4" } }