fix(server-detail): restore auto-escape via macro-call blocks + extract console_form macro

Replace four raw-string | safe config_field calls with {% call config_field_block %}
blocks so Jinja auto-escaping is preserved for server.hostname, server.name,
blueprint.name, server.rcon_password and g.user.username. Extract a console_form
macro to eliminate the duplicated inline/modal form and restore the missing
placeholder on the modal input. Add XSS regression test that confirms the fix
is load-bearing (test fails when templates are reverted to pre-fix state).

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

l4d2web/l4d2web/templates/_macros.html

@@ -8,3 +8,29 @@
     <div class="config-field-value">{{ value }}</div>
   </div>
 {% endmacro %}
+
+{# Block form of config_field: lets the caller write the value as a Jinja
+   template body, which keeps auto-escaping active for interpolated values. #}
+{% macro config_field_block(label, editable=False) %}
+  <div class="config-field">
+    <div class="config-field-label">{{ label }}</div>
+    <div class="config-field-value">{{ caller() }}</div>
+  </div>
+{% endmacro %}
+
+{# Console form — used by both the inline tab and the modal. The transcript
+   ID differs per location to keep HTMX swaps independent. #}
+{% macro console_form(server, transcript_id) %}
+  <form hx-post="/servers/{{ server.id }}/console"
+        hx-target="#{{ transcript_id }}"
+        hx-swap="beforeend"
+        hx-on::after-request="this.command.value=''; this.command.focus()"
+        class="console-input-form"
+        data-console-form data-server-id="{{ server.id }}">
+    <input type="hidden" name="csrf_token" value="{{ session.get('csrf_token', '') }}">
+    <span class="console-prompt-glyph">&gt;</span>
+    <input name="command" autocomplete="off" spellcheck="false" maxlength="1000"
+           placeholder="status, changelevel c1m1_hotel, sm_kick …">
+    <button type="submit">Send</button>
+  </form>
+{% endmacro %}

l4d2web/l4d2web/templates/server_detail.html

@@ -18,35 +18,33 @@
            hx-trigger="load, every 5s"
            hx-swap="innerHTML"></section>
 
-  {# Config grid — flat auto-fit; uses config_field macro from _macros.html #}
+  {# Config grid — flat auto-fit; uses config_field_block macro from _macros.html #}
   <div class="config-grid">
-    {{ macros.config_field(
-        "Port",
-        ('<a href="steam://run/550//+connect%20' ~ connect_host ~ ':' ~ server.port ~ '">' ~ server.port ~ '</a>') | safe
-    ) }}
-    {{ macros.config_field(
-        "Blueprint",
-        (('<a href="/blueprints/' ~ blueprint.id ~ '">' ~ blueprint.name ~ '</a>') | safe) if blueprint else "—"
-    ) }}
-    {{ macros.config_field(
-        "RCON",
-        (
-          '<span class="password-mask" data-password-field="' ~ server.id ~ '">••••••••••••</span>'
-          ~ '<span class="password-value" data-password-field="' ~ server.id ~ '" hidden>' ~ server.rcon_password ~ '</span> '
-          ~ '<button class="link-button" data-password-toggle="' ~ server.id ~ '" aria-label="Show RCON password">show</button>'
-        ) | safe
-    ) }}
-    {{ macros.config_field(
-        "Hostname",
-        (
-          '<form method="post" action="/servers/' ~ server.id ~ '" class="inline-save">'
-          ~ '<input type="hidden" name="csrf_token" value="' ~ session.get('csrf_token', '') ~ '">'
-          ~ '<input name="hostname" value="' ~ server.hostname ~ '" placeholder="' ~ g.user.username ~ ' ' ~ server.name ~ '" maxlength="128">'
-          ~ '<button type="submit">Save</button>'
-          ~ '</form>'
-        ) | safe,
-        editable=True
-    ) }}
+    {% call macros.config_field_block("Port") %}
+      <a href="steam://run/550//+connect%20{{ connect_host }}:{{ server.port }}">{{ server.port }}</a>
+    {% endcall %}
+
+    {% call macros.config_field_block("Blueprint") %}
+      {% if blueprint %}
+        <a href="/blueprints/{{ blueprint.id }}">{{ blueprint.name }}</a>
+      {% else %}
+        —
+      {% endif %}
+    {% endcall %}
+
+    {% call macros.config_field_block("RCON") %}
+      <span class="password-mask" data-password-field="{{ server.id }}">••••••••••••</span>
+      <span class="password-value" data-password-field="{{ server.id }}" hidden>{{ server.rcon_password }}</span>
+      <button class="link-button" data-password-toggle="{{ server.id }}" aria-label="Show RCON password">show</button>
+    {% endcall %}
+
+    {% call macros.config_field_block("Hostname", editable=True) %}
+      <form method="post" action="/servers/{{ server.id }}" class="inline-save">
+        <input type="hidden" name="csrf_token" value="{{ session.get('csrf_token', '') }}">
+        <input name="hostname" value="{{ server.hostname }}" placeholder="{{ g.user.username }} {{ server.name }}" maxlength="128">
+        <button type="submit">Save</button>
+      </form>
+    {% endcall %}
   </div>
 </section>
 
@@ -71,18 +69,7 @@
         {% endwith %}
       {% endfor %}
     </div>
-    <form hx-post="/servers/{{ server.id }}/console"
-          hx-target="#console-transcript-inline-{{ server.id }}"
-          hx-swap="beforeend"
-          hx-on::after-request="this.command.value=''; this.command.focus()"
-          class="console-input-form"
-          data-console-form data-server-id="{{ server.id }}">
-      <input type="hidden" name="csrf_token" value="{{ session.get('csrf_token', '') }}">
-      <span class="console-prompt-glyph">&gt;</span>
-      <input name="command" autocomplete="off" spellcheck="false" maxlength="1000"
-             placeholder="status, changelevel c1m1_hotel, sm_kick …">
-      <button type="submit">Send</button>
-    </form>
+    {{ macros.console_form(server, "console-transcript-inline-" ~ server.id) }}
   </div>
 
   <div role="tabpanel" data-tab="files" class="tab-pane" hidden>
@@ -128,17 +115,7 @@
         {% endwith %}
       {% endfor %}
     </div>
-    <form hx-post="/servers/{{ server.id }}/console"
-          hx-target="#console-transcript-modal-{{ server.id }}"
-          hx-swap="beforeend"
-          hx-on::after-request="this.command.value=''; this.command.focus()"
-          class="console-input-form"
-          data-console-form data-server-id="{{ server.id }}">
-      <input type="hidden" name="csrf_token" value="{{ session.get('csrf_token', '') }}">
-      <span class="console-prompt-glyph">&gt;</span>
-      <input name="command" autocomplete="off" spellcheck="false" maxlength="1000">
-      <button type="submit">Send</button>
-    </form>
+    {{ macros.console_form(server, "console-transcript-modal-" ~ server.id) }}
   </div>
 </dialog>
 

l4d2web/tests/test_servers.py

@@ -752,6 +752,36 @@ def test_update_server_clears_hostname(user_client_with_blueprints) -> None:
         assert server.hostname == ""
 
 
+def test_server_detail_escapes_hostname(user_client_with_blueprints) -> None:
+    """Hostname containing HTML must be escaped, not rendered as markup.
+    Regression guard for the macro-call refactor that ensures Jinja
+    auto-escaping is preserved on the config grid."""
+    from sqlalchemy import select
+    from l4d2web.models import Server
+
+    client, data = user_client_with_blueprints
+
+    with session_scope() as db:
+        server = Server(
+            user_id=data["user_id"],
+            blueprint_id=data["blueprint_id"],
+            name="xss-test",
+            port=27299,
+            rcon_password="x",
+            hostname='<script>alert("xss")</script>',
+        )
+        db.add(server)
+        db.flush()
+        server_id = server.id
+
+    resp = client.get(f"/servers/{server_id}")
+    assert resp.status_code == 200
+    body = resp.get_data(as_text=True)
+    # The literal tag must not appear; the escaped form must.
+    assert "<script>alert(" not in body
+    assert "&lt;script&gt;" in body
+
+
 def test_server_detail_renders_state_cluster_and_inspection_strip(user_client_with_blueprints) -> None:
     from sqlalchemy import select