Hand-Icon als App-/Tray-Icon, App heißt ai-control, Tests für Keychain/Key-Status

- Icons komplett aus hand.png regeneriert (tauri icon)
- Tray-Icon explizit per include_bytes (cargo trackt die Datei) und als
  Template-Icon für helle/dunkle Menüleiste; tauri-Feature image-png
- Cargo-Paket app -> ai-control, Fenstertitel ai-control
- Tests: keychain_service-Suffix gegen verifizierten Referenzwert,
  hasCredentials-Status (Key vorhanden/leer/fehlt)

src-tauri/Cargo.toml

@@ -1,8 +1,8 @@
 [package]
-name = "app"
+name = "ai-control"
 version = "0.1.0"
-description = "A Tauri App"
-authors = ["you"]
+description = "Pool- und Session-Verwaltung für Claude Code"
+authors = ["marcus.hinz"]
 license = ""
 repository = ""
 edition = "2021"
@@ -21,7 +21,7 @@ tauri-build = { version = "2.6.3", features = [] }
 serde_json = "1.0"
 serde = { version = "1.0", features = ["derive"] }
 log = "0.4"
-tauri = { version = "2.11.3", features = ["tray-icon"] }
+tauri = { version = "2.11.3", features = ["tray-icon", "image-png"] }
 tauri-plugin-log = "2"
 tauri-plugin-autostart = "2"
 tauri-plugin-dialog = "2"