chore(release): bump version to 0.9.3 and package release assets

- Add CHANGELOG entry for v0.9.3
- Bump version to 0.9.3 across Cargo.toml, Cargo.lock, THREAT_MODEL.md, SECURITY_AUDIT.md, Scoop, and WinGet manifests
- Package and sign Windows (.zip, .exe) and Linux musl (.tar.gz, sanctum) binaries with Minisign

packages/scoop/sanctum.json

@@ -1,12 +1,12 @@
 {
-  "version": "0.9.2",
+  "version": "0.9.3",
   "description": "Verschlüsselter Ein-Datei-Container unter Windows im reinen Userland via WebDAV",
   "homepage": "https://gitea.pansi.eu/harald/sanctum",
   "license": "MIT",
   "architecture": {
     "64bit": {
-      "url": "https://gitea.pansi.eu/harald/sanctum/releases/download/v0.9.2/sanctum-v0.9.2-windows-x86_64.zip",
-      "hash": "5828fca32b7d0581b740ef4f3cfb21c3717f92ee80d2e3f62e953a1ef083ac18",
+      "url": "https://gitea.pansi.eu/harald/sanctum/releases/download/v0.9.3/sanctum-v0.9.3-windows-x86_64.zip",
+      "hash": "75611155008ed0ecd6e6bbbb77fc549c5884ecc5779ca3012e66852bbb3b729b",
       "bin": "sanctum.exe"
     }
   },