feat(drafts): clone per-user drafts when forking a workspace

`clone_workspace_data` clones every other workspace-scoped table on
fork creation (resources, variables, scripts, flows, apps, raw apps,
triggers, schedules) but quietly dropped the `draft` table. With
per-user drafts that meant any open editor in the parent lost its
pending edits the moment a fork was created — surprising and
inconsistent with how forks treat the deployed surface.

New `clone_drafts` mirrors the existing clone helpers: a single
INSERT...SELECT into the target workspace, preserving `path`, `typ`,
`value`, `created_at`, and `email`. The `email` FK targets
`password.email` which is instance-scoped so it carries across
workspaces without remap. `created_at` is preserved on purpose so the
per-tab `last_sync` baseline lines up with the parent's timeline —
otherwise the fork's next autosave would race a stale `last_sync`
and trip the conflict modal on every cloned draft.

Plain INSERT (not UPSERT) is safe because the fork target is empty at
create time; no conflict against the partial unique indexes
(`draft_pkey_with_user` / `draft_pkey_legacy`). The synthetic
BIGSERIAL `id` PK is regenerated by the default so it stays out of
the column list.

backend/.sqlx/query-a8c3f6e53ae6bf257c610031ba8e21eb719f2cf78748b0b35fe742a941839158.json

@@ -0,0 +1,15 @@
+{
+  "db_name": "PostgreSQL",
+  "query": "INSERT INTO draft (workspace_id, path, typ, value, created_at, email)\n         SELECT $2, path, typ, value, created_at, email\n         FROM draft\n         WHERE workspace_id = $1",
+  "describe": {
+    "columns": [],
+    "parameters": {
+      "Left": [
+        "Text",
+        "Varchar"
+      ]
+    },
+    "nullable": []
+  },
+  "hash": "a8c3f6e53ae6bf257c610031ba8e21eb719f2cf78748b0b35fe742a941839158"
+}

backend/windmill-api-workspaces/src/workspaces.rs

@@ -3867,6 +3867,10 @@ async fn clone_workspace_data(
     // Clone raw apps
     clone_raw_apps(tx, source_workspace_id, target_workspace_id).await?;
 
+    // Clone per-user drafts (and the legacy NULL-email workspace draft,
+    // if any) so users picking up the fork keep their pending edits.
+    clone_drafts(tx, source_workspace_id, target_workspace_id).await?;
+
     // Clone workspace runnable dependencies and dependency map
     clone_workspace_runnable_dependencies(tx, source_workspace_id, target_workspace_id).await?;
 
@@ -4708,6 +4712,35 @@ async fn clone_raw_apps(
     Ok(())
 }
 
+/// Clone every per-user draft (and the legacy NULL-email workspace draft,
+/// if present) from the parent. The fork target is empty at create time so
+/// a plain INSERT is safe — no need to UPSERT against the partial unique
+/// indexes (`draft_pkey_with_user` / `draft_pkey_legacy`). `id` is the
+/// BIGSERIAL synthetic PK and is regenerated by the default; we don't list
+/// it in the column set. `created_at` is preserved so the per-tab
+/// `last_sync` baseline the editor reads (`?get_draft=true` → overlay's
+/// `draft_saved_at`) lines up with the parent's timeline — otherwise the
+/// fork's first POST from any open editor would race a stale `last_sync`
+/// and trip the conflict modal on every cloned draft.
+async fn clone_drafts(
+    tx: &mut Transaction<'_, Postgres>,
+    source_workspace_id: &str,
+    target_workspace_id: &str,
+) -> Result<()> {
+    sqlx::query!(
+        "INSERT INTO draft (workspace_id, path, typ, value, created_at, email)
+         SELECT $2, path, typ, value, created_at, email
+         FROM draft
+         WHERE workspace_id = $1",
+        source_workspace_id,
+        target_workspace_id,
+    )
+    .execute(&mut **tx)
+    .await?;
+
+    Ok(())
+}
+
 async fn clone_workspace_runnable_dependencies(
     tx: &mut Transaction<'_, Postgres>,
     source_workspace_id: &str,