feat: add configuration model and appsettings.json

src/SpamGuard/Configuration/SpamGuardOptions.cs

@@ -0,0 +1,36 @@
+namespace SpamGuard.Configuration;
+
+public sealed class SpamGuardOptions
+{
+    public const string SectionName = "SpamGuard";
+
+    public ImapOptions Imap { get; set; } = new();
+    public ClaudeOptions Claude { get; set; } = new();
+    public MonitoringOptions Monitoring { get; set; } = new();
+}
+
+public sealed class ImapOptions
+{
+    public string Host { get; set; } = "";
+    public int Port { get; set; } = 993;
+    public bool UseSsl { get; set; } = true;
+    public string Username { get; set; } = "";
+    public string Password { get; set; } = "";
+}
+
+public sealed class ClaudeOptions
+{
+    public string ApiKey { get; set; } = "";
+    public string Model { get; set; } = "claude-sonnet-4-6";
+    public int MaxBodyLength { get; set; } = 2000;
+}
+
+public sealed class MonitoringOptions
+{
+    public int PollIntervalSeconds { get; set; } = 60;
+    public int TrustedSenderRefreshMinutes { get; set; } = 60;
+    public double SpamConfidenceThreshold { get; set; } = 0.7;
+    public string SpamFolderName { get; set; } = "Junk";
+    public int InitialScanDays { get; set; } = 7;
+    public int MaxActivityLogEntries { get; set; } = 500;
+}

src/SpamGuard/appsettings.json

@@ -0,0 +1,38 @@
+{
+  "SpamGuard": {
+    "Imap": {
+      "Host": "imap.example.com",
+      "Port": 993,
+      "UseSsl": true,
+      "Username": "user@example.com",
+      "Password": ""
+    },
+    "Claude": {
+      "ApiKey": "",
+      "Model": "claude-sonnet-4-6",
+      "MaxBodyLength": 2000
+    },
+    "Monitoring": {
+      "PollIntervalSeconds": 60,
+      "TrustedSenderRefreshMinutes": 60,
+      "SpamConfidenceThreshold": 0.7,
+      "SpamFolderName": "Junk",
+      "InitialScanDays": 7,
+      "MaxActivityLogEntries": 500
+    }
+  },
+  "Serilog": {
+    "MinimumLevel": "Information",
+    "WriteTo": [
+      { "Name": "Console" },
+      {
+        "Name": "File",
+        "Args": {
+          "path": "%APPDATA%/SpamGuard/logs/spamguard-.log",
+          "rollingInterval": "Day",
+          "retainedFileCountLimit": 7
+        }
+      }
+    ]
+  }
+}