Dissolve System Settings into individual settings pages

The monolithic tab page competed with the settings rail as a second
navigation system, and its Integrations tab was a dumping ground. Each
section is now its own routed rail page (ServiceNow, Zabbix Supplies,
Dell Warranty, Collector PC Types, Branding, Floor Map, Printing and
Labels, Email/SMTP, Audit, Authentication, Asset Identifiers, Global
Search), thin over a shared useSystemSettings composable, grouped
logically in the rail with system groups clustered last. Old
/settings/system?tab= URLs redirect to the right page.

Also fixes the post-login redirect: the auth guard now remembers the
intended destination and Login returns there (same-site paths only).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

frontend/src/views/settings/FloorMapSettings.vue

@@ -0,0 +1,100 @@
+<template>
+  <div>
+    <div class="page-header">
+      <h2>Floor Map</h2>
+    </div>
+
+    <div class="section-card">
+      <div class="setting-group">
+        <h3>Facility Blueprint</h3>
+        <p class="setting-description">
+          The floor-plan image and its pixel dimensions for this facility. Map
+          markers are positioned against these dimensions, so the width and
+          height must match the native size of the blueprint image. Leave the
+          image paths at their defaults to use the bundled sitemap.
+        </p>
+
+        <div class="setting-row">
+          <label>
+            <span>Blueprint image (light theme)</span>
+            <input
+              type="text"
+              v-model="settings.map_blueprint_light"
+              placeholder="/static/images/sitemap2025-light.png"
+              @blur="saveSetting('map_blueprint_light', settings.map_blueprint_light)"
+              :disabled="saving"
+            >
+            <div class="map-upload-row">
+              <input type="file" accept="image/*" @change="uploadBlueprint('light', $event)" :disabled="mapUploading" />
+              <img v-if="settings.map_blueprint_light" :src="settings.map_blueprint_light" class="map-thumb" alt="light blueprint" />
+            </div>
+            <small class="input-hint">Upload an image, or type a path/URL to the light-theme floor plan</small>
+          </label>
+        </div>
+
+        <div class="setting-row">
+          <label>
+            <span>Blueprint image (dark theme)</span>
+            <input
+              type="text"
+              v-model="settings.map_blueprint_dark"
+              placeholder="/static/images/sitemap2025-dark.png"
+              @blur="saveSetting('map_blueprint_dark', settings.map_blueprint_dark)"
+              :disabled="saving"
+            >
+            <div class="map-upload-row">
+              <input type="file" accept="image/*" @change="uploadBlueprint('dark', $event)" :disabled="mapUploading" />
+              <img v-if="settings.map_blueprint_dark" :src="settings.map_blueprint_dark" class="map-thumb map-thumb-dark" alt="dark blueprint" />
+            </div>
+            <small class="input-hint">Upload an image, or type a path/URL to the dark-theme floor plan</small>
+          </label>
+        </div>
+
+        <div class="setting-row">
+          <label>
+            <span>Blueprint width (pixels)</span>
+            <input
+              type="number"
+              v-model="settings.map_width"
+              min="1"
+              placeholder="3300"
+              @blur="saveSetting('map_width', settings.map_width)"
+              :disabled="saving"
+            >
+            <small class="input-hint">Native pixel width of the blueprint image</small>
+          </label>
+        </div>
+
+        <div class="setting-row">
+          <label>
+            <span>Blueprint height (pixels)</span>
+            <input
+              type="number"
+              v-model="settings.map_height"
+              min="1"
+              placeholder="2550"
+              @blur="saveSetting('map_height', settings.map_height)"
+              :disabled="saving"
+            >
+            <small class="input-hint">Native pixel height of the blueprint image</small>
+          </label>
+        </div>
+      </div>
+    </div>
+
+    <div v-if="error" class="error-message">{{ error }}</div>
+    <div v-if="success" class="settings-success">{{ success }}</div>
+  </div>
+</template>
+
+<script setup>
+import { onMounted } from 'vue'
+import { useSystemSettings } from '../../composables/systemSettings'
+
+const {
+  settings, saving, mapUploading, error, success,
+  loadSettings, saveSetting, uploadBlueprint,
+} = useSystemSettings()
+
+onMounted(loadSettings)
+</script>