v0.166.0: mobile nav off-canvas drawer + sidebar cleanup + versioned logo/favicon URLs

Mobile nav was broken — the <=768px block predated the v0.146.0 accordion and
flattened .nav-links into a horizontal overflow-x strip, clipping the accordion's
nested sub-lists. Replaced with a sticky top bar + off-canvas left drawer that
reuses the vertical sidebar (accordion untouched), plus a no-js static fallback.
Removed the sidebar customer-name span (kept on login). Added ?v={{.Version}}
cache-bust to logo/favicon URLs (Cloudflare 4h edge-cache; 0.126.1 failure mode).

Part 4 (outlined-logo constant swap) gated out per §3a: live felhom.eu main still
serves a logo.svg with live <text>/font-family; constants unchanged.

5 new tests via the real layout/CSS render; nav_accordion invariants unchanged.

controller/internal/web/templates/style.css

@@ -100,12 +100,6 @@ body {
     display: block;
     margin: 0 auto 0.5rem;
 }
-.customer-name {
-    display: block;
-    font-size: .85rem;
-    color: var(--text-2);
-    margin-top: .25rem;
-}
 .nav-links {
     list-style: none;
     padding: 1rem 0;
@@ -142,6 +136,26 @@ body {
 .version { color: var(--text-3); }
 .logout-link { color: var(--text-3); text-decoration: none; transition: color 0.2s ease; }
 .logout-link:hover { color: var(--blue-bright); }
+/* Mobile chrome (v0.166.0) — hidden by default so desktop (>768px) stays pixel-identical; the
+   ≤768px block below turns the top bar on and converts the sidebar into an off-canvas drawer. */
+.mobile-topbar { display: none; }
+.nav-backdrop { display: none; }
+.nav-burger {
+    display: flex;
+    align-items: center;
+    padding: .375rem;
+    background: none;
+    border: none;
+    color: var(--text-2);
+    cursor: pointer;
+    transition: color 0.2s ease;
+}
+.nav-burger:hover { color: var(--blue-bright); }
+.nav-burger:focus-visible {
+    outline: 2px solid var(--blue-bright);
+    outline-offset: -2px;
+}
+.nav-burger .ico { width: 24px; height: 24px; }
 
 /* Main content */
 .content {
@@ -2532,10 +2546,54 @@ a.stat-card:hover {
 
 /* Responsive */
 @media(max-width: 768px) {
-    .sidebar { width: 100%; height: auto; position: relative; border-right: none; border-bottom: 1px solid var(--line); }
-    .nav-links { display: flex; padding: 0; overflow-x: auto; }
-    .nav-links a { padding: .5rem 1rem; white-space: nowrap; }
-    .nav-links a.active { border-left: none; border-bottom: 2px solid var(--blue); }
+    /* v0.166.0: the old horizontal .nav-links strip was deleted — it predated the v0.146.0
+       accordion and, because the nested sub-lists share the .nav-links class, laid them out
+       horizontally inside an overflow:hidden row and clipped every sub-item past the first.
+       Replaced by a sticky top bar + off-canvas drawer (JS) with a static-sidebar fallback (no-JS). */
+    .mobile-topbar {
+        display: flex;
+        align-items: center;
+        justify-content: space-between;
+        position: sticky;
+        top: 0;
+        z-index: 800;
+        background: var(--bg-2);
+        border-bottom: 1px solid var(--line);
+        padding: .5rem 1rem;
+    }
+    .mobile-topbar-logo img { height: 36px; width: auto; display: block; }
+    /* JS path: the vertical sidebar becomes an off-canvas left drawer (accordion untouched). */
+    .js .sidebar {
+        position: fixed;
+        top: 0;
+        left: 0;
+        height: 100vh;
+        height: 100dvh;
+        width: min(280px, 85vw);
+        transform: translateX(-100%);
+        transition: transform .2s ease;
+        z-index: 950;
+        border-right: 1px solid var(--line);
+        border-bottom: none;
+    }
+    .js .sidebar.is-open { transform: none; }
+    .js .nav-backdrop:not([hidden]) {
+        display: block;
+        position: fixed;
+        inset: 0;
+        background: rgba(0, 0, 0, .5);
+        z-index: 900;
+    }
+    body.nav-open { overflow: hidden; }
+    /* No-JS fallback: sidebar renders static inline above the content so no destination dead-ends. */
+    .no-js .sidebar {
+        position: static;
+        height: auto;
+        width: 100%;
+        border-right: none;
+        border-bottom: 1px solid var(--line);
+    }
+    .no-js .nav-burger { display: none; }
     .content { margin-left: 0; padding: 1rem; }
     body { flex-direction: column; }
     .app-row { flex-wrap: wrap; }
@@ -2552,6 +2610,10 @@ a.stat-card:hover {
     .restore-label { min-width: auto; }
     .restore-select { max-width: 100%; }
 }
+/* v0.166.0: honor reduced-motion for the drawer slide, matching the accordion/chevron convention. */
+@media (prefers-reduced-motion: reduce) {
+    .js .sidebar { transition: none; }
+}
 
 /* ===================================================================
    Storage Init Wizard & Migration UI