fix(web): clearer topology/identity copy, capped description width, mobile More-nav, preset spacing

Console polish on the Virtual displays card + shell:
- Topology help now leads with the streamed display's role (Extend/Primary/Exclusive) instead of
  the confusing physical-monitor-only framing; notes the headless case. Identity help spells out the
  actual behavior (stable per-client identity → the desktop reapplies that client's scaling/resolution
  on reconnect) + what Shared / Per-client / Per-client+resolution each do.
- Cap description/help width at max-w-prose so long help text isn't a full-viewport line on large screens.
- Mobile bottom nav: 8 flat tabs were too cramped → 4 pinned tabs + a "More" tab whose sheet holds the
  rest (Performance/Logs/Pairing/Settings), "More" highlighted when the active route is in the overflow.
- More breathing room under the "Preset" heading.

web tsc + biome + vite build green.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web/messages/de.json

@@ -9,6 +9,7 @@
 	"nav_pairing": "Kopplung",
 	"nav_library": "Bibliothek",
 	"nav_settings": "Einstellungen",
+	"nav_more": "Mehr",
 	"status_title": "Live-Status",
 	"status_video": "Video",
 	"status_audio": "Audio",
@@ -87,7 +88,7 @@
 	"display_preset_current": "Aktiv",
 	"display_preset_soon": "in Kürze",
 	"display_keep_alive_help": "„Aus“ baut die Anzeige sofort beim Trennen ab. Halte sie (und bei gamescope ihr Spiel) am Leben, damit ein schnelles Wiederverbinden sofort fortsetzt, statt neu aufzubauen.",
-	"display_topology_help": "Was mit den physischen Monitoren des Hosts während des Streamings geschieht.",
+	"display_topology_help": "Wie sich die gestreamte Anzeige in den Desktop des Hosts einfügt. Erweitern: ein zusätzlicher Bildschirm neben deinen Monitoren. Primär: die gestreamte Anzeige wird der primäre Ausgang, deine Monitore bleiben. Exklusiv: die gestreamte Anzeige ist der einzige Ausgang — physische Monitore werden beim Streamen deaktiviert und danach wiederhergestellt. Auf einem Host ohne Monitor legt es nur fest, ob die gestreamte Anzeige primär ist.",
 	"display_conflict": "Wenn ein weiterer Client verbindet",
 	"display_conflict_help": "Was passiert, wenn ein zweiter Client verbindet, während bereits gestreamt wird, und eine andere Auflösung anfragt.",
 	"display_conflict_separate": "Eigene Anzeige",
@@ -95,7 +96,7 @@
 	"display_conflict_join": "Ansicht teilen",
 	"display_conflict_reject": "Besetzt — ablehnen",
 	"display_identity": "Client-Identität",
-	"display_identity_help": "Jedem Client eine stabile Anzeige geben, damit der Desktop seine Monitor-Einstellungen merkt (z. B. Skalierung).",
+	"display_identity_help": "Ob die gestreamte Anzeige eine stabile Client-Identität trägt, sodass der Desktop des Hosts die Monitor-Einstellungen dieses Clients (Skalierung, Auflösung) merkt und beim erneuten Verbinden wieder anwendet. Geteilt: eine Identität für alle. Pro Client: jedes Gerät eigene. Pro Client + Auflösung: separate Einstellungen je Gerät und Auflösung.",
 	"display_identity_shared": "Geteilt",
 	"display_identity_per_client": "Pro Client",
 	"display_identity_per_client_mode": "Pro Client + Auflösung",

web/messages/en.json

@@ -9,6 +9,7 @@
 	"nav_pairing": "Pairing",
 	"nav_library": "Library",
 	"nav_settings": "Settings",
+	"nav_more": "More",
 	"status_title": "Live status",
 	"status_video": "Video",
 	"status_audio": "Audio",
@@ -87,7 +88,7 @@
 	"display_preset_current": "Active",
 	"display_preset_soon": "coming soon",
 	"display_keep_alive_help": "Off tears the display down as soon as the client disconnects. Keep it alive (and, on gamescope, its game) so a quick reconnect resumes instantly instead of rebuilding.",
-	"display_topology_help": "What happens to the host's physical monitors while streaming.",
+	"display_topology_help": "How the streamed display fits into the host's desktop. Extend: an extra screen alongside your monitors. Primary: the streamed display becomes the primary output, your monitors kept. Exclusive: the streamed display is the sole output — physical monitors are disabled while streaming and restored after. On a headless host it just sets whether the streamed display is the primary.",
 	"display_conflict": "When another client connects",
 	"display_conflict_help": "What happens if a second client connects while one is already streaming and asks for a different resolution.",
 	"display_conflict_separate": "Own display",
@@ -95,7 +96,7 @@
 	"display_conflict_join": "Share view",
 	"display_conflict_reject": "Busy — reject",
 	"display_identity": "Per-client identity",
-	"display_identity_help": "Give each client a stable display so the desktop remembers its per-monitor settings (e.g. scaling).",
+	"display_identity_help": "Whether the streamed display carries a stable per-client identity, so the host's desktop remembers that client's per-monitor settings (scaling, resolution) and reapplies them when it reconnects. Shared: one identity for everyone. Per client: each device keeps its own. Per client + resolution: a device keeps separate settings per resolution it connects at.",
 	"display_identity_shared": "Shared",
 	"display_identity_per_client": "Per client",
 	"display_identity_per_client_mode": "Per client + resolution",