feat(FN-2471): persist source issue provenance in task storage

- Add TaskSourceIssue contract and thread sourceIssue through Task, TaskCreateInput, archived task entries, and TaskStore serialization paths.
- Extend SQLite schema to v45 with sourceIssue* columns and add migration coverage for v44 upgrades plus legacy JSON migration import.
- Persist, update, clear, and archive/unarchive sourceIssue metadata in TaskStore with dedicated regression tests.
- Update core and dashboard tests to schema v45 expectations and stabilize flaky modal assertions with async waits.

packages/dashboard/app/components/__tests__/ModelOnboardingModal.test.tsx

@@ -3678,9 +3678,11 @@ describe("ModelOnboardingModal progressive disclosure", () => {
         expect(screen.getByText("Create Your First Task")).toBeTruthy();
       });
 
-      const aiProviderItem = getReadinessItem("AI Provider");
-      expect(aiProviderItem).toHaveAttribute("data-status", "skipped");
-      expect(aiProviderItem).toHaveTextContent(/AI agents won't be available/i);
+      await waitFor(() => {
+        const aiProviderItem = getReadinessItem("AI Provider");
+        expect(aiProviderItem).toHaveAttribute("data-status", "skipped");
+        expect(aiProviderItem).toHaveTextContent(/AI agents won't be available/i);
+      });
     });
 
     it("shows GitHub as missing when available but not connected", async () => {

packages/dashboard/app/components/__tests__/SettingsModal.test.tsx

@@ -3078,7 +3078,7 @@ describe("SettingsModal", () => {
     render(<SettingsModal onClose={onClose} addToast={addToast} />);
     await waitFor(() => expect(fetchSettings).toHaveBeenCalled());
 
-    fireEvent.click(screen.getByText("Scheduling"));
+    fireEvent.click(await screen.findByText("Scheduling"));
     const checkbox = screen.getByLabelText("Enable automatic task archiving");
     expect(checkbox).toBeTruthy();
     expect(checkbox.getAttribute("type")).toBe("checkbox");