feat(ui): landing page redesign — apps grid + roadmap placeholders

Slice 4 of the on-box UI uplevel. The landing page is now the peak-end
first impression after install: welcome + hostname chip, a "Your apps"
tile grid consuming /api/apps (with the real icon and an app-specific
primary action — fileshare gets smb://<host>.local/files, everything
else falls back to Manage →), the existing system-status tiles kept
intact, and a subtle "Coming next" row of text-only links that jump to
the planned-features section on furtka.org. No dead tiles.

The status script now also writes ip_primary, kernel, ram_total and a
furtka_version read from /etc/furtka/version (TODO: pin that file at
install time; for now it reports "dev"). The settings page will
consume those in slice 5.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

webinstaller/app.py

@@ -1,3 +1,7 @@
+# ruff: noqa: E501 — inline HTML/CSS/JS payloads (_INDEX_HTML, _STYLE_CSS,
+# _CADDYFILE, _FURTKA_STATUS_SH, etc.) round-trip verbatim to the installed
+# system; wrapping them hurts readability and the rendered output is what
+# matters.
 import base64
 import json
 import os
@@ -192,7 +196,14 @@ _INDEX_HTML = """\
             <p class="host">Running on <code>__HOSTNAME__</code></p>
         </header>
 
-        <section class="status">
+        <section>
+            <h2>Your apps</h2>
+            <div id="apps-section" class="grid-apps">
+                <a class="app-tile" href="/apps"><span class="name">Loading…</span></a>
+            </div>
+        </section>
+
+        <section>
             <h2>System status</h2>
             <div class="tiles">
                 <div class="tile">
@@ -211,9 +222,17 @@ _INDEX_HTML = """\
             <p class="updated">Updated <span id="updated">—</span></p>
         </section>
 
-        <section class="soon">
+        <section>
-            <h2>Apps</h2>
+            <h2>Coming next</h2>
-            <p><a href="/apps">Manage installed apps →</a></p>
+            <div class="coming">
+                <p class="hint">Features we're building — follow progress on <a href="https://furtka.org">furtka.org</a>.</p>
+                <a href="https://furtka.org/#planned">Photos</a>
+                <a href="https://furtka.org/#planned">Smart home</a>
+                <a href="https://furtka.org/#planned">Media streaming</a>
+                <a href="https://furtka.org/#planned">Multiple boxes</a>
+                <a href="https://furtka.org/#planned">Secure link</a>
+                <a href="https://furtka.org/#planned">User accounts</a>
+            </div>
         </section>
 
         <footer>
@@ -222,9 +241,56 @@ _INDEX_HTML = """\
     </main>
 
     <script>
+        const HOSTNAME = "__HOSTNAME__";
+        const FALLBACK_ICON = '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.5" stroke-linecap="round" stroke-linejoin="round"><path d="M3 7v12a2 2 0 0 0 2 2h14a2 2 0 0 0 2-2V9a2 2 0 0 0-2-2h-7l-2-2H5a2 2 0 0 0-2 2z"/></svg>';
+
+        function esc(s) {
+            const d = document.createElement('div');
+            d.textContent = s == null ? '' : String(s);
+            return d.innerHTML;
+        }
+
+        function primaryAction(app) {
+            // Only fileshare has a direct "open" link today. Future apps with
+            // HTTP endpoints would surface a URL here; everything else falls
+            // back to the /apps manage page.
+            if (app.name === 'fileshare') {
+                return { href: `smb://${HOSTNAME}.local/files`, label: 'Open files' };
+            }
+            return { href: '/apps', label: 'Manage →' };
+        }
+
+        async function renderApps() {
+            const target = document.getElementById('apps-section');
+            try {
+                const r = await fetch('/api/apps', { cache: 'no-store' });
+                if (!r.ok) throw new Error('api');
+                const apps = (await r.json()).filter(a => a.ok !== false);
+                if (!apps.length) {
+                    target.innerHTML = '<a class="app-tile" href="/apps">' +
+                        '<span class="name">No apps yet</span>' +
+                        '<span class="cta">Install your first app →</span></a>';
+                    return;
+                }
+                target.innerHTML = apps.map(a => {
+                    const icon = a.icon_svg || FALLBACK_ICON;
+                    const { href, label } = primaryAction(a);
+                    return `<a class="app-tile" href="${esc(href)}">
+                        <div class="icon">${icon}</div>
+                        <span class="name">${esc(a.display_name || a.name)}</span>
+                        <span class="cta">${esc(label)}</span>
+                    </a>`;
+                }).join('');
+            } catch (e) {
+                target.innerHTML = '<a class="app-tile" href="/apps">' +
+                    '<span class="name">Manage apps</span>' +
+                    '<span class="cta">Open →</span></a>';
+            }
+        }
+
         async function refresh() {
             try {
-                const r = await fetch('/status.json', {cache: 'no-store'});
+                const r = await fetch('/status.json', { cache: 'no-store' });
                 if (!r.ok) return;
                 const s = await r.json();
                 document.getElementById('uptime').textContent = s.uptime || '—';
@@ -235,6 +301,8 @@ _INDEX_HTML = """\
                 /* next tick will retry */
             }
         }
+
+        renderApps();
         refresh();
         setInterval(refresh, 15000);
     </script>
@@ -657,6 +725,10 @@ _STATUS_JSON_PLACEHOLDER = """\
   "uptime": "starting…",
   "docker_version": "starting…",
   "disk_free": "starting…",
+  "ip_primary": "",
+  "kernel": "",
+  "ram_total": "",
+  "furtka_version": "",
   "updated_at": ""
 }
 """
@@ -679,6 +751,13 @@ else
     docker_version=unavailable
 fi
 disk_free=$(df -h / 2>/dev/null | awk 'NR==2 {print $4 " free of " $2}' || echo unknown)
+ip_primary=$(ip -4 -o addr show scope global 2>/dev/null \
+    | awk '{print $4}' | cut -d/ -f1 | head -1 || true)
+kernel=$(uname -r 2>/dev/null || echo unknown)
+ram_total=$(free -h --si 2>/dev/null | awk '/^Mem:/ {print $2}' || echo unknown)
+# TODO(furtka-version): wire into the installer so /etc/furtka/version
+# gets pinned at install time. Until then the settings page shows "dev".
+furtka_version=$(cat /etc/furtka/version 2>/dev/null || echo dev)
 updated_at=$(date -Iseconds)
 
 cat > "$tmp" <<EOF
@@ -687,6 +766,10 @@ cat > "$tmp" <<EOF
   "uptime": "$uptime",
   "docker_version": "$docker_version",
   "disk_free": "$disk_free",
+  "ip_primary": "$ip_primary",
+  "kernel": "$kernel",
+  "ram_total": "$ram_total",
+  "furtka_version": "$furtka_version",
   "updated_at": "$updated_at"
 }
 EOF