Decouple core Yaak logic from Tauri (#354)

crates/yaak-core/src/context.rs

@@ -0,0 +1,56 @@
+use std::path::PathBuf;
+
+/// Context for a workspace operation.
+///
+/// In Tauri, this is extracted from the WebviewWindow URL.
+/// In CLI, this is constructed from command arguments or config.
+#[derive(Debug, Clone, Default)]
+pub struct WorkspaceContext {
+    pub workspace_id: Option<String>,
+    pub environment_id: Option<String>,
+    pub cookie_jar_id: Option<String>,
+    pub request_id: Option<String>,
+}
+
+impl WorkspaceContext {
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    pub fn with_workspace(mut self, workspace_id: impl Into<String>) -> Self {
+        self.workspace_id = Some(workspace_id.into());
+        self
+    }
+
+    pub fn with_environment(mut self, environment_id: impl Into<String>) -> Self {
+        self.environment_id = Some(environment_id.into());
+        self
+    }
+
+    pub fn with_cookie_jar(mut self, cookie_jar_id: impl Into<String>) -> Self {
+        self.cookie_jar_id = Some(cookie_jar_id.into());
+        self
+    }
+
+    pub fn with_request(mut self, request_id: impl Into<String>) -> Self {
+        self.request_id = Some(request_id.into());
+        self
+    }
+}
+
+/// Application context trait for accessing app-level resources.
+///
+/// This abstracts over Tauri's `AppHandle` for path resolution and app identity.
+/// Implemented by Tauri's AppHandle and by CLI's own context struct.
+pub trait AppContext: Send + Sync + Clone {
+    /// Returns the path to the application data directory.
+    /// This is where the database and other persistent data are stored.
+    fn app_data_dir(&self) -> PathBuf;
+
+    /// Returns the application identifier (e.g., "app.yaak.desktop").
+    /// Used for keyring access and other platform-specific features.
+    fn app_identifier(&self) -> &str;
+
+    /// Returns true if running in development mode.
+    fn is_dev(&self) -> bool;
+}