refactor: added UI-only tool result summary to all the tools; move summary generation logic to tool's own ts file

src/agent/tools/AddNotesTool.test.ts

@@ -0,0 +1,70 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+import { AddNotesTool } from './AddNotesTool';
+import { KGCore } from '../../core/KGCore';
+import { KGProject } from '../../core/KGProject';
+import { KGMidiTrack } from '../../core/track/KGMidiTrack';
+import { KGMidiRegion } from '../../core/region/KGMidiRegion';
+
+const storeState = {
+  activeRegionId: null as string | null,
+};
+
+vi.mock('../../stores/projectStore', () => ({
+  useProjectStore: {
+    getState: () => storeState,
+  },
+}));
+
+describe('AddNotesTool', () => {
+  beforeEach(() => {
+    storeState.activeRegionId = null;
+    vi.restoreAllMocks();
+  });
+
+  it('builds a compact summary for successful note creation', () => {
+    const track = new KGMidiTrack('Lead', 1);
+    const region = new KGMidiRegion('region-1', track.getId().toString(), track.getTrackIndex(), 'Verse Melody', 0, 32);
+    track.setRegions([region]);
+    const project = new KGProject('summary-project', 8, 0, 120, { numerator: 4, denominator: 4 }, 'C major');
+    project.setTracks([track]);
+    storeState.activeRegionId = region.getId();
+
+    vi.spyOn(KGCore, 'instance').mockReturnValue({
+      getCurrentProject: () => project,
+      getSelectedItems: () => [],
+    } as unknown as KGCore);
+
+    const tool = new AddNotesTool();
+    const summary = tool.buildToolResultDisplayContent(
+      {
+        notes: [
+          { pitch: 'C4', start: 16, length: 4 },
+          { pitch: 'E4', start: 20, length: 8 },
+        ],
+      },
+      { success: true, result: 'raw result' },
+    );
+
+    expect(summary).toBe(
+      'Successfully created 2 notes in region **Verse Melody** on track **Lead**, spanning bars 5 to 7.'
+    );
+  });
+
+  it('returns no compact summary when the target region cannot be resolved', () => {
+    const project = new KGProject('summary-project', 8, 0, 120, { numerator: 4, denominator: 4 }, 'C major');
+    vi.spyOn(KGCore, 'instance').mockReturnValue({
+      getCurrentProject: () => project,
+      getSelectedItems: () => [],
+    } as unknown as KGCore);
+
+    const tool = new AddNotesTool();
+    const summary = tool.buildToolResultDisplayContent(
+      {
+        notes: [{ pitch: 'C4', start: 0, length: 4 }],
+      },
+      { success: true, result: 'raw result' },
+    );
+
+    expect(summary).toBeUndefined();
+  });
+});