v0.21.0 — System health banner with colored indicators + tooltips

New row between top bar and content showing pill-shaped status indicators
for the system dependencies that PROSERVE needs (SteamVR, Vive Business
Streaming process, VR headset reachable on the network, etc.). Each pill
is colored : 🟢 OK, 🟠 limitation détectée (e.g. ping élevé), 🔴 KO,
gris = non configuré. Hover → tooltip with full check kind, target,
last RTT/process count and timestamp.

Architecture
- LocalConfig.HealthChecksConfig : list of HealthCheckEntry (Kind=Ping
  or Process, Target=IP/host or process name, ping thresholds in ms,
  refresh interval in s).
- ISystemHealthService + SystemHealthService : ping via
  System.Net.NetworkInformation.Ping (no admin required), process
  lookup via System.Diagnostics.Process.GetProcessesByName. Returns
  HealthResult { Severity, Detail }.
- HealthIndicatorViewModel : observable wrapper per entry with
  Severity-driven Brushes (background pill, border, icon colour) and
  composed Tooltip text.
- MainViewModel.InitHealthIndicators + StartHealthLoop : populates
  ObservableCollection<HealthIndicatorViewModel> from config and runs
  parallel checks every RefreshIntervalSeconds (default 10s).
- MainWindow.xaml : new Row 1 (between top bar and body) hosting an
  ItemsControl bound to HealthIndicators. Row collapses cleanly if the
  list is empty (HasHealthIndicators=false).

Defaults shipped (all editable in %LocalAppData%\PSLauncher\config.json)
- 🎮 SteamVR (Process : vrserver)
- 📡 Vive Business Streaming (Process : HtcConnectionUtility)
- 🥽 Casque VR (Ping : empty, user fills in the headset IP)

The Settings UI editor for managing the list is intentionally deferred
to a future iteration — config.json edit is enough to start using it.

Versions bumped to 0.21.0.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/PSLauncher.Models/LocalConfig.cs

@@ -64,6 +64,14 @@ public sealed class LocalConfig
     /// </summary>
     public DocToolConfig DocTool { get; set; } = new();
 
+    /// <summary>
+    /// Surveillance d'état système affichée en bandeau sous la top bar
+    /// (pings d'IP, processus requis comme SteamVR / Vive Business Streaming…).
+    /// Chaque check a un statut Vert (OK) / Orange (warn, ex. ping élevé) / Rouge
+    /// (KO). Tooltip détaillé au survol.
+    /// </summary>
+    public HealthChecksConfig HealthChecks { get; set; } = new();
+
     /// <summary>
     /// Connexion à la base MySQL locale (XAMPP) utilisée par PROSERVE pour ses
     /// statistiques. Le launcher s'en sert pour appliquer les migrations bundled
@@ -142,6 +150,74 @@ public sealed class DocToolConfig
     public int MaxBackups { get; set; } = 3;
 }
 
+public sealed class HealthChecksConfig
+{
+    /// <summary>Période de re-vérification, en secondes. 0 = désactivé.</summary>
+    public int RefreshIntervalSeconds { get; set; } = 10;
+
+    /// <summary>
+    /// Liste des checks à effectuer. Defaults = exemples typiques setup VR
+    /// (SteamVR + Vive Business Streaming + ping casque). L'utilisateur édite
+    /// la liste via <c>%LocalAppData%\PSLauncher\config.json</c> pour ajuster
+    /// les noms de processus, IPs et seuils ; un éditeur Settings est prévu
+    /// en v2 si le besoin est récurrent.
+    /// </summary>
+    public List<HealthCheckEntry> Checks { get; set; } = new()
+    {
+        new HealthCheckEntry
+        {
+            Name = "SteamVR",
+            Icon = "🎮",
+            Kind = "Process",
+            Target = "vrserver",
+        },
+        new HealthCheckEntry
+        {
+            Name = "Vive Business Streaming",
+            Icon = "📡",
+            Kind = "Process",
+            Target = "HtcConnectionUtility",
+        },
+        new HealthCheckEntry
+        {
+            Name = "Casque VR",
+            Icon = "🥽",
+            Kind = "Ping",
+            Target = "",   // À remplir avec l'IP réseau du casque ; vide = check désactivé
+            PingWarnMs = 50,
+            PingErrorMs = 200,
+            PingTimeoutMs = 1000,
+        },
+    };
+}
+
+public sealed class HealthCheckEntry
+{
+    /// <summary>Libellé affiché dans le bandeau, ex. "SteamVR".</summary>
+    public string Name { get; set; } = "";
+
+    /// <summary>Pictogramme emoji affiché à côté du nom, ex. "🎮", "📡", "🥽".</summary>
+    public string Icon { get; set; } = "🔌";
+
+    /// <summary>"Process" ou "Ping" (case-insensitive).</summary>
+    public string Kind { get; set; } = "Process";
+
+    /// <summary>
+    /// Selon Kind : nom du processus (sans .exe) pour Process,
+    /// IP/hostname pour Ping. Vide = check ignoré (statut Unknown).
+    /// </summary>
+    public string Target { get; set; } = "";
+
+    /// <summary>Pour Ping : RTT au-dessus duquel le statut passe en Warning (Orange). Default 50 ms.</summary>
+    public int? PingWarnMs { get; set; } = 50;
+
+    /// <summary>Pour Ping : RTT au-dessus duquel le statut passe en Error (Rouge). Default 200 ms.</summary>
+    public int? PingErrorMs { get; set; } = 200;
+
+    /// <summary>Pour Ping : timeout de la requête ICMP. Default 1 s.</summary>
+    public int? PingTimeoutMs { get; set; } = 1000;
+}
+
 public sealed class LicenseConfig
 {
     public string? EncryptedKey { get; set; }