web: parse imprint contact from mdx file at runtim

web/Dockerfile

@@ -75,6 +75,7 @@ COPY --chown=potatomesh:potatomesh web/lib ./lib
 COPY --chown=potatomesh:potatomesh web/spec ./spec
 COPY --chown=potatomesh:potatomesh web/public ./public
 COPY --chown=potatomesh:potatomesh web/views ./views
+COPY --chown=potatomesh:potatomesh web/content ./content
 COPY --chown=potatomesh:potatomesh web/scripts ./scripts
 
 # Copy SQL schema files from data directory

web/content/imprint.mdx

@@ -0,0 +1,32 @@
+<!--
+  Copyright © 2025-26 l5yth & contributors
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+-->
+
+---
+title: Imprint
+contact: maintainer@potato-mesh.invalid
+---
+
+## Contact
+
+For legal notices and service-related inquiries, contact:
+
+- PotatoMesh maintainers
+- Email: maintainer@potato-mesh.invalid
+- Project: [github.com/l5yth/potato-mesh](https://github.com/l5yth/potato-mesh)
+
+## Responsible For Content
+
+PotatoMesh contributors maintain this service on a best-effort basis for community mesh visibility and troubleshooting.

web/lib/potato_mesh/application.rb

@@ -58,6 +58,7 @@ require_relative "application/meshtastic/payload_decoder"
 require_relative "application/data_processing"
 require_relative "application/filesystem"
 require_relative "application/instances"
+require_relative "application/content/mdx_page"
 require_relative "application/routes/api"
 require_relative "application/routes/ingest"
 require_relative "application/routes/root"

web/lib/potato_mesh/application/content/mdx_page.rb

@@ -0,0 +1,207 @@
+# Copyright © 2025-26 l5yth & contributors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# frozen_string_literal: true
+
+require "yaml"
+require "rack/utils"
+
+module PotatoMesh
+  module App
+    module Content
+      # Parse MDX/Markdown content files with optional frontmatter and produce
+      # a sanitised HTML payload for static pages.
+      module MdxPage
+        module_function
+
+        DEFAULT_METADATA = {
+          "title" => "Imprint",
+        }.freeze
+
+        # Resolve the absolute source path for a page slug under web/content.
+        #
+        # @param slug [String] page identifier without extension.
+        # @return [String] absolute path to the corresponding .mdx file.
+        def source_path_for(slug)
+          File.expand_path("#{slug}.mdx", content_root)
+        end
+
+        # Load and render an MDX page by slug. Missing or unreadable files are
+        # mapped to a friendly fallback payload instead of raising.
+        #
+        # @param slug [String] page identifier without extension.
+        # @return [Hash] metadata/body payload ready for view rendering.
+        def load(slug)
+          path = source_path_for(slug)
+          return fallback_payload unless File.file?(path) && File.readable?(path)
+
+          raw_content = File.read(path)
+          metadata, body_markdown = extract_frontmatter(raw_content)
+          rendered_html = markdown_to_html(body_markdown)
+
+          {
+            "found" => true,
+            "title" => metadata["title"] || DEFAULT_METADATA["title"],
+            "metadata" => metadata,
+            "body_html" => PotatoMesh::Sanitizer.sanitize_rendered_html(rendered_html),
+          }
+        rescue Errno::EACCES, Errno::ENOENT
+          fallback_payload
+        end
+
+        # Extract optional YAML frontmatter from a markdown file.
+        #
+        # @param content [String] full source file content.
+        # @return [Array<Hash, String>] parsed metadata and markdown body.
+        def extract_frontmatter(content)
+          return [{}, content.to_s] unless content.is_a?(String)
+
+          normalized = content.dup
+          normalized.sub!(/\A\uFEFF/, "")
+
+          while (match = normalized.match(/\A\s*<!--.*?-->\s*/m))
+            normalized = normalized[match[0].length..]
+          end
+
+          frontmatter_match = normalized.match(/\A---\s*\n(?<meta>.*?)\n---\s*\n?/m)
+          return [{}, normalized] unless frontmatter_match
+
+          metadata = parse_metadata(frontmatter_match[:meta])
+          remaining = normalized[frontmatter_match[0].length..].to_s
+          [metadata, remaining]
+        end
+
+        # Convert YAML metadata into a flat string hash used by templates.
+        #
+        # @param raw_frontmatter [String] YAML frontmatter body.
+        # @return [Hash] parsed key/value metadata.
+        def parse_metadata(raw_frontmatter)
+          parsed = YAML.safe_load(raw_frontmatter, permitted_classes: [], aliases: false)
+          return {} unless parsed.is_a?(Hash)
+
+          parsed.each_with_object({}) do |(key, value), metadata|
+            next if key.nil?
+            next if value.nil?
+
+            metadata[key.to_s] = value.to_s
+          end
+        rescue Psych::Exception
+          {}
+        end
+
+        # Render markdown to HTML while disabling embedded raw HTML parsing in
+        # the markdown stage; output is sanitised by the caller.
+        #
+        # @param markdown [String] markdown source content.
+        # @return [String] rendered HTML output.
+        def markdown_to_html(markdown)
+          lines = markdown.to_s.gsub("\r\n", "\n").split("\n")
+          rendered = []
+          in_list = false
+
+          lines.each do |line|
+            content = line.strip
+            if content.empty?
+              if in_list
+                rendered << "</ul>"
+                in_list = false
+              end
+              next
+            end
+
+            heading_match = content.match(/\A(#{Regexp.union("###", "##", "#")})\s+(.+)\z/)
+            if heading_match
+              if in_list
+                rendered << "</ul>"
+                in_list = false
+              end
+              level = heading_match[1].length
+              rendered << "<h#{level}>#{render_inline_markdown(heading_match[2])}</h#{level}>"
+              next
+            end
+
+            list_match = content.match(/\A[-*]\s+(.+)\z/)
+            if list_match
+              unless in_list
+                rendered << "<ul>"
+                in_list = true
+              end
+              rendered << "<li>#{render_inline_markdown(list_match[1])}</li>"
+              next
+            end
+
+            if in_list
+              rendered << "</ul>"
+              in_list = false
+            end
+            rendered << "<p>#{render_inline_markdown(content)}</p>"
+          end
+
+          rendered << "</ul>" if in_list
+          rendered.join("\n")
+        end
+
+        # Render inline markdown links while escaping plain text segments.
+        #
+        # @param text [String] source markdown text for a single block.
+        # @return [String] escaped inline HTML fragment.
+        def render_inline_markdown(text)
+          source = text.to_s
+          index = 0
+          output = +""
+          link_pattern = /\[([^\]]+)\]\(([^)]+)\)/
+
+          while (match = link_pattern.match(source, index))
+            output << Rack::Utils.escape_html(source[index...match.begin(0)])
+
+            label = Rack::Utils.escape_html(match[1].to_s)
+            href = match[2].to_s.strip
+            if href.match?(/\Ahttps?:\/\/[^\s]+\z/i)
+              output << "<a href=\"#{Rack::Utils.escape_html(href)}\" target=\"_blank\" rel=\"noreferrer noopener\">#{label}</a>"
+            else
+              output << Rack::Utils.escape_html(match[0].to_s)
+            end
+            index = match.end(0)
+          end
+
+          output << Rack::Utils.escape_html(source[index..].to_s)
+          output
+        end
+
+        # Return the absolute content directory path relative to the web app
+        # root, so loading works in local runs and container builds.
+        #
+        # @return [String] absolute content directory path.
+        def content_root
+          app_root = File.expand_path("../../../../", __dir__)
+          File.expand_path("content", app_root)
+        end
+
+        # Build a stable fallback payload used when content is unavailable.
+        #
+        # @return [Hash] fallback response consumed by the imprint view.
+        def fallback_payload
+          {
+            "found" => false,
+            "title" => DEFAULT_METADATA["title"],
+            "metadata" => {},
+            "body_html" => PotatoMesh::Sanitizer.sanitize_rendered_html(
+              "<p>The imprint content is currently unavailable. Please try again later.</p>",
+            ),
+          }
+        end
+      end
+    end
+  end
+end

web/lib/potato_mesh/application/routes/root.rb

@@ -77,6 +77,13 @@ module PotatoMesh
             erb template, layout: :"layouts/app", locals: merged_locals
           end
 
+          # Load static imprint content from the repository-backed MDX source.
+          #
+          # @return [Hash] rendered imprint payload with title/body metadata.
+          def imprint_content_payload
+            PotatoMesh::App::Content::MdxPage.load("imprint")
+          end
+
           # Remove keys with +nil+ values from the provided hash, returning a
           # shallow copy. Hash#compact is only available in newer Ruby
           # versions; this helper keeps behaviour consistent across supported
@@ -191,6 +198,20 @@ module PotatoMesh
             render_root_view(:federation, view_mode: :federation)
           end
 
+          app.get "/imprint" do
+            imprint_payload = imprint_content_payload
+            render_root_view(
+              :imprint,
+              view_mode: :imprint,
+              extra_locals: {
+                imprint_title: imprint_payload["title"],
+                imprint_metadata: imprint_payload["metadata"],
+                imprint_body_html: imprint_payload["body_html"],
+                imprint_content_found: imprint_payload["found"],
+              },
+            )
+          end
+
           app.get "/nodes/:id" do
             node_ref = params.fetch("id", nil)
             reference_payload = build_node_detail_reference(node_ref)

web/lib/potato_mesh/sanitizer.rb

@@ -246,5 +246,20 @@ module PotatoMesh
 
       distance
     end
+
+    # Apply a lightweight HTML sanitization pass for static page content.
+    # The sanitizer removes executable tags and event handlers, and prevents
+    # javascript/data/file URLs from being emitted in href/src attributes.
+    #
+    # @param html [Object] generated HTML string.
+    # @return [String] sanitized HTML safe for rendering in templates.
+    def sanitize_rendered_html(html)
+      value = html.to_s.dup
+      value.gsub!(%r{<\s*(script|style|iframe|object|embed)[^>]*>.*?<\s*/\s*\1\s*>}mi, "")
+      value.gsub!(/\s+on[a-z]+\s*=\s*(['"]).*?\1/mi, "")
+      value.gsub!(/\s+on[a-z]+\s*=\s*[^\s>]+/mi, "")
+      value.gsub!(/\s+(href|src)\s*=\s*(['"])\s*(?:javascript|data|file):.*?\2/mi, "")
+      value
+    end
   end
 end

web/public/assets/styles/base.css

@@ -1190,6 +1190,39 @@ body.dark .node-detail-overlay__close:hover {
   color: #c62828;
 }
 
+.imprint-page {
+  padding: 24px var(--pad) 40px;
+  max-width: 860px;
+  margin: 0 auto;
+}
+
+.imprint-page__intro h2 {
+  margin: 0 0 8px;
+}
+
+.imprint-page__status {
+  margin: 0;
+  color: var(--muted);
+}
+
+.imprint-page__content {
+  margin-top: 20px;
+  line-height: 1.6;
+}
+
+.imprint-page__content h1,
+.imprint-page__content h2,
+.imprint-page__content h3 {
+  margin-top: 1.2em;
+  margin-bottom: 0.45em;
+}
+
+.imprint-page__content p,
+.imprint-page__content ul,
+.imprint-page__content ol {
+  margin: 0 0 0.9em;
+}
+
 .node-detail {
   width: 100%;
   margin: 0;

web/spec/app_spec.rb

@@ -1402,6 +1402,46 @@ RSpec.describe "Potato Mesh Sinatra app" do
     end
   end
 
+  describe "GET /imprint" do
+    it "renders the imprint page content" do
+      get "/imprint"
+
+      expect(last_response).to be_ok
+      expect(last_response.body).to include("Contact")
+      expect(last_response.body).to include("maintainer@potato-mesh.invalid")
+      expect(last_response.body).to include('<section class="imprint-page">')
+    end
+
+    it "renders a friendly fallback when the source file is missing" do
+      allow(PotatoMesh::App::Content::MdxPage).to receive(:source_path_for)
+                                                    .with("imprint")
+                                                    .and_return("/tmp/potatomesh-missing-imprint.mdx")
+
+      get "/imprint"
+
+      expect(last_response).to be_ok
+      expect(last_response.body).to include("The configured imprint document could not be read.")
+      expect(last_response.body).to include("The imprint content is currently unavailable. Please try again later.")
+    end
+
+    it "marks imprint as active in desktop and mobile navigation" do
+      get "/imprint"
+
+      expect(last_response).to be_ok
+      expect(last_response.body).to include('href="/imprint" class="site-nav__link is-active"')
+      expect(last_response.body).to include('href="/imprint" class="mobile-nav__link is-active"')
+      expect(last_response.body).to include('href="/imprint" class="site-nav__link is-active" aria-current="page"')
+      expect(last_response.body).to include('href="/imprint" class="mobile-nav__link is-active" aria-current="page"')
+    end
+
+    it "shows imprint links in both navigation menus and footer" do
+      get "/"
+
+      expect(last_response).to be_ok
+      expect(last_response.body.scan('href="/imprint"').length).to be >= 3
+    end
+  end
+
   describe "GET /chat" do
     it "renders the chat container when chat is enabled" do
       get "/chat"

web/views/imprint.erb

@@ -0,0 +1,26 @@
+<!--
+  Copyright © 2025-26 l5yth & contributors
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+-->
+<section class="imprint-page">
+  <header class="imprint-page__intro">
+    <h2><%= Rack::Utils.escape_html(imprint_title.to_s) %></h2>
+    <% unless imprint_content_found %>
+      <p class="imprint-page__status">The configured imprint document could not be read.</p>
+    <% end %>
+  </header>
+  <article class="imprint-page__content">
+    <%= imprint_body_html %>
+  </article>
+</section>

web/views/layouts/app.erb

@@ -68,7 +68,7 @@
 <% body_classes = []
    body_classes << "dark" if initial_theme == "dark"
    view_mode = (defined?(current_view_mode) && current_view_mode) ? current_view_mode.to_sym : :dashboard
-   full_screen_view = view_mode != :dashboard
+   full_screen_view = !%i[dashboard imprint].include?(view_mode)
    body_classes << "view-#{view_mode}"
    shell_classes = ["page-shell"]
    shell_classes << "page-shell--full-screen" if full_screen_view
@@ -77,12 +77,12 @@
    main_classes << "page-main--full-screen" if full_screen_view
    show_header = true
    show_meta_info = true
-   show_auto_refresh_controls = view_mode != :federation
+   show_auto_refresh_controls = !%i[federation imprint].include?(view_mode)
    show_auto_fit_toggle = %i[dashboard map].include?(view_mode)
    map_zoom_override = defined?(map_zoom) ? map_zoom : nil
    show_info_button = true
    show_footer = !full_screen_view
-   show_filter_input = !%i[node_detail charts federation].include?(view_mode)
+   show_filter_input = !%i[node_detail charts federation imprint].include?(view_mode)
    show_auto_refresh_toggle = show_auto_refresh_controls
    show_refresh_actions = show_auto_refresh_controls || view_mode == :federation
    nodes_nav_href = "/nodes"
@@ -133,6 +133,7 @@
             <a href="/chat" class="site-nav__link<%= view_mode == :chat ? " is-active" : "" %>"<%= view_mode == :chat ? ' aria-current="page"' : "" %>>Chat</a>
             <a href="<%= nodes_nav_href %>" class="site-nav__link<%= nodes_nav_active ? " is-active" : "" %>"<%= nodes_nav_active ? ' aria-current="page"' : "" %>>Nodes</a>
             <a href="/charts" class="site-nav__link<%= view_mode == :charts ? " is-active" : "" %>"<%= view_mode == :charts ? ' aria-current="page"' : "" %>>Charts</a>
+            <a href="/imprint" class="site-nav__link<%= view_mode == :imprint ? " is-active" : "" %>"<%= view_mode == :imprint ? ' aria-current="page"' : "" %>>Imprint</a>
             <% if federation_nav_enabled %>
               <a href="/federation" class="site-nav__link js-federation-nav<%= view_mode == :federation ? " is-active" : "" %>" data-federation-label="Federation"<%= view_mode == :federation ? ' aria-current="page"' : "" %>>Federation</a>
             <% end %>
@@ -164,6 +165,7 @@
             <a href="/chat" class="mobile-nav__link<%= view_mode == :chat ? " is-active" : "" %>"<%= view_mode == :chat ? ' aria-current="page"' : "" %>>Chat</a>
             <a href="<%= nodes_nav_href %>" class="mobile-nav__link<%= nodes_nav_active ? " is-active" : "" %>"<%= nodes_nav_active ? ' aria-current="page"' : "" %>>Nodes</a>
             <a href="/charts" class="mobile-nav__link<%= view_mode == :charts ? " is-active" : "" %>"<%= view_mode == :charts ? ' aria-current="page"' : "" %>>Charts</a>
+            <a href="/imprint" class="mobile-nav__link<%= view_mode == :imprint ? " is-active" : "" %>"<%= view_mode == :imprint ? ' aria-current="page"' : "" %>>Imprint</a>
             <% if federation_nav_enabled %>
               <a href="/federation" class="mobile-nav__link js-federation-nav<%= view_mode == :federation ? " is-active" : "" %>" data-federation-label="Federation"<%= view_mode == :federation ? ' aria-current="page"' : "" %>>Federation</a>
             <% end %>
@@ -267,6 +269,8 @@
           <span class="footer-links">
             GitHub:
             <a href="https://github.com/l5yth/potato-mesh" target="_blank">l5yth/potato-mesh</a>
+            <span class="footer-separator" aria-hidden="true">—</span>
+            <a href="/imprint">Imprint</a>
             <% if contact_link && !contact_link.empty? %>
               <span class="footer-separator" aria-hidden="true">—</span>
               <span class="footer-contact">