feat: adapt all pages for mobile (Galaxy S10, 360px)

- Remove min-width: 580px from body — was forcing horizontal scroll
- Reduce container padding to px-2 on mobile
- Fix .inv width (was 400px fixed, now auto)
- Add @media (max-width: 575.98px) block: smaller card margins,
  font sizes, full-width forms and select bars
- Audit/owner/admin/inspection forms: col-auto → col-12 col-sm-auto
- Inspection stats: col-md-3 → col-6 col-md-3 (2x2 grid on mobile)
- Inspection action buttons: d-flex flex-wrap gap-2
- Home search input: flex-grow-1 to fill available width
- aud-select-bar: stacks vertically on mobile
- Bump cache-busting version for styles.css and app.js

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

frontend/styles.css

@@ -5,7 +5,7 @@
 
 body {
     background-color: #E2F3FD;
-    min-width: 580px;
+    min-width: 0;
 }
 
 .row {
@@ -125,7 +125,8 @@ td.inv-col, th.inv-col {
 }
 
 .inv {
-    width: 400px;
+    width: auto;
+    min-width: 80px;
 }
 
 .rasp {
@@ -158,6 +159,69 @@ td.inv-col, th.inv-col {
     width: 200px;
 }
 
+@media (max-width: 575.98px) {
+    header h1 {
+        font-size: 1.2rem;
+    }
+
+    .container-fluid {
+        padding-left: 8px !important;
+        padding-right: 8px !important;
+    }
+
+    .card {
+        margin: 4px;
+        border-radius: 10px;
+    }
+
+    .rasp {
+        width: auto;
+        max-width: 120px;
+    }
+
+    .table td, .table th {
+        font-size: 12px;
+        padding: 4px 3px;
+    }
+
+    .aud-select-bar {
+        flex-direction: column !important;
+        align-items: stretch !important;
+        justify-content: flex-start !important;
+    }
+
+    .aud-select-bar label {
+        margin-bottom: 4px;
+    }
+
+    .aud-select-bar select,
+    .aud-select-bar .btn {
+        width: 100% !important;
+        max-width: 100% !important;
+    }
+
+    .form-row-mobile {
+        flex-direction: column !important;
+    }
+
+    .form-row-mobile .col-auto,
+    .form-row-mobile [class*="col-"] {
+        width: 100% !important;
+        max-width: 100% !important;
+    }
+
+    .btn-bar {
+        display: flex;
+        flex-wrap: wrap;
+        gap: 8px;
+    }
+
+    .btn-bar .btn {
+        flex: 1 1 auto;
+        margin: 0 !important;
+    }
+}
+
 @media print {
     * {
         font-family: "Times New Roman", Times, serif;