Fix layout icone en-tete: redimensionnement 24x24 avant affichage

Changements :
- Redimensionnement de l'icone PNG a 24x24 via CatmullRom (golang.org/x/image/draw)
- Corrige le decalage de l'interface cause par l'image 912x1164

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

go.sum

@@ -2,6 +2,8 @@ github.com/lxn/walk v0.0.0-20210112085537-c389da54e794 h1:NVRJ0Uy0SOFcXSKLsS65Om
 github.com/lxn/walk v0.0.0-20210112085537-c389da54e794/go.mod h1:E23UucZGqpuUANJooIbHWCufXvOcT6E7Stq81gU+CSQ=
 github.com/lxn/win v0.0.0-20210218163916-a377121e959e h1:H+t6A/QJMbhCSEH5rAuRxh+CtW96g0Or0Fxa9IKr4uc=
 github.com/lxn/win v0.0.0-20210218163916-a377121e959e/go.mod h1:KxxjdtRkfNoYDCUP5ryK7XJJNTnpC8atvtmTheChOtk=
+golang.org/x/image v0.38.0 h1:5l+q+Y9JDC7mBOMjo4/aPhMDcxEptsX+Tt3GgRQRPuE=
+golang.org/x/image v0.38.0/go.mod h1:/3f6vaXC+6CEanU4KJxbcUZyEePbyKbaLoDOe4ehFYY=
 golang.org/x/sys v0.0.0-20201018230417-eeed37f84f13/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.18.0 h1:DBdB3niSjOA/O0blCZBqDefyWNYveAYMNF1Wum0DYQ4=
 golang.org/x/sys v0.18.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=