Share one exporter, and flush the file before saying it is written (#686)

Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

crates/yaak-models/src/export.rs

@@ -0,0 +1,33 @@
+//! Building an export document.
+//!
+//! Here rather than in `yaak` because the whole of it is this crate: a connection, the
+//! resources, and JSON. Putting it where the browser can reach it too is what keeps a
+//! tab's export from being a second implementation that drifts.
+
+use crate::error::Result;
+use crate::query_manager::QueryManager;
+use crate::util::get_workspace_export_resources;
+
+pub struct ExportDataParams<'a> {
+    pub query_manager: &'a QueryManager,
+    pub yaak_version: &'a str,
+    pub workspace_ids: Vec<&'a str>,
+    pub include_private_environments: bool,
+}
+
+/// The export document, as JSON.
+///
+/// Returned rather than written: where an export goes is the host's to decide, and a browser
+/// tab has no path to be handed. The desktop hands the bytes to its save dialog, the CLI
+/// writes them, a tab downloads them. None of that is this function's business.
+pub fn export_data(params: ExportDataParams<'_>) -> Result<String> {
+    let db = params.query_manager.connect();
+    let export_data = get_workspace_export_resources(
+        &db,
+        params.yaak_version,
+        params.workspace_ids,
+        params.include_private_environments,
+    )?;
+
+    Ok(serde_json::to_string_pretty(&export_data)?)
+}

crates/yaak-models/src/lib.rs

@@ -13,6 +13,7 @@ pub mod client_db;
 mod connection_or_tx;
 pub mod cookies;
 pub mod error;
+pub mod export;
 pub mod migrate;
 pub mod models;
 pub mod models_ops;