feat(modules): expose min-chunk, max-chunk, delay-us, extraArgs as Nix options

Allows tuning fragmentation parameters for performance.
Defaults match CLI defaults (min 3, max 8, delay 500us).

modules/darwin.nix

@@ -12,9 +12,10 @@ in
 
   config = lib.mkIf cfg.enable {
     launchd.user.agents.ihtc = {
-      command = "${self.packages.${system}.ihtc}/bin/ihtc --listen 127.0.0.1:${toString cfg.port} --refrag ${toString cfg.refrag} --auto-proxy"
+      command = "${self.packages.${system}.ihtc}/bin/ihtc --listen 127.0.0.1:${toString cfg.port} --min-chunk ${toString cfg.minChunk} --max-chunk ${toString cfg.maxChunk} --delay-us ${toString cfg.delayUs} --refrag ${toString cfg.refrag} --auto-proxy"
         + lib.optionalString cfg.verbose " --verbose"
-        + lib.optionalString (cfg.patterns != [ ]) " --regex '${regex}'";
+        + lib.optionalString (cfg.patterns != [ ]) " --regex '${regex}'"
+        + lib.optionalString (cfg.extraArgs != [ ]) " ${builtins.concatStringsSep " " cfg.extraArgs}";
       serviceConfig = {
         RunAtLoad = true;
         KeepAlive = true;

modules/nixos.nix

@@ -15,9 +15,10 @@ in
       description = "ihtc DPI bypass proxy";
       wantedBy = [ "default.target" ];
       serviceConfig = {
-        ExecStart = "${self.packages.${system}.ihtc}/bin/ihtc --listen 127.0.0.1:${toString cfg.port} --refrag ${toString cfg.refrag}"
+        ExecStart = "${self.packages.${system}.ihtc}/bin/ihtc --listen 127.0.0.1:${toString cfg.port} --min-chunk ${toString cfg.minChunk} --max-chunk ${toString cfg.maxChunk} --delay-us ${toString cfg.delayUs} --refrag ${toString cfg.refrag}"
           + lib.optionalString cfg.verbose " --verbose"
-          + lib.optionalString (cfg.patterns != [ ]) " --regex '${regex}'";
+          + lib.optionalString (cfg.patterns != [ ]) " --regex '${regex}'"
+          + lib.optionalString (cfg.extraArgs != [ ]) " ${builtins.concatStringsSep " " cfg.extraArgs}";
         Restart = "always";
       };
     };

modules/options.nix

@@ -23,6 +23,30 @@ in
       description = "Minimum chunk count for ClientHello (0 = disabled)";
     };
 
+    minChunk = mkOption {
+      type = types.int;
+      default = 3;
+      description = "Minimum bytes per fragment";
+    };
+
+    maxChunk = mkOption {
+      type = types.int;
+      default = 8;
+      description = "Maximum bytes per fragment";
+    };
+
+    delayUs = mkOption {
+      type = types.int;
+      default = 500;
+      description = "Max microsecond delay between fragments (0 to disable)";
+    };
+
+    extraArgs = mkOption {
+      type = types.listOf types.str;
+      default = [ ];
+      description = "Extra CLI arguments passed to ihtc";
+    };
+
     verbose = mkOption {
       type = types.bool;
       default = false;