Initial import: shopdb-flask multi-site asset platform

Flask + Vue rewrite of the classic-ASP shopdb, built as a plugin
framework so sister GE Aerospace sites can adopt it. Product version
0.7.0-pre-0.8.0, plugin contract 0.11.0, 966 backend tests.

Key entry points:
- docs/INSTALL-WINDOWS-IIS.md - tested Windows + IIS install runbook
  (own-site and subpath deployment methods)
- docs/PILOT-DEPLOY.md - production pilot: stand up + import + verify
- docs/IMPORT-API.md - schema-agnostic legacy data import contract
- scripts/site_imports/wjf/ - West Jefferson reference import loader
- docs/adr/ - twelve accepted architecture decision records

frontend/src/views/settings/AssetIdentifiersSettings.vue

@@ -0,0 +1,58 @@
+<template>
+  <div>
+    <div class="page-header">
+      <h2>Asset Identifiers</h2>
+    </div>
+
+    <div class="section-card">
+      <div class="setting-group">
+        <p class="setting-description">
+          Enable or disable optional asset identifiers per asset type. When disabled
+          for a type, the identifier is hidden from that type's forms and detail
+          pages across the system.
+        </p>
+
+        <div class="table-container">
+          <table class="identifier-matrix">
+            <thead>
+              <tr>
+                <th>Identifier</th>
+                <th v-for="col in assetTypeCols" :key="col.key">{{ col.label }}</th>
+              </tr>
+            </thead>
+            <tbody>
+              <tr v-for="row in identifierRows" :key="row.name">
+                <td class="identifier-name">{{ row.label }}</td>
+                <td v-for="col in assetTypeCols" :key="col.key">
+                  <button
+                    class="toggle-btn"
+                    :class="{ active: matrixValue(row.name, col.key) }"
+                    @click="toggleIdentifier(row.name, col.key)"
+                    :disabled="saving"
+                  >
+                    <span class="toggle-slider"></span>
+                  </button>
+                </td>
+              </tr>
+            </tbody>
+          </table>
+        </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, identifierRows, assetTypeCols } from '../../composables/systemSettings'
+
+const {
+  saving, error, success,
+  loadSettings, matrixValue, toggleIdentifier,
+} = useSystemSettings()
+
+onMounted(loadSettings)
+</script>