test(e2e): phase-2 add Office and zip smoke automation (#714)

* test(e2e): phase-2 add office and zip smoke coverage

* test(e2e): address copilot review for fixture stability and CI python setup

* test(e2e): fix preflight fixture scope and path handling

* test(e2e): harden fixture preflight and remove duplicate generation

* test(e2e): remove redundant zip install and cleanup temp zip dir

* test(e2e): ensure zip dependency and unify python command in docs

* docs(e2e): align README with npm gen scripts and python3 usage

tests/e2e/scripts/generate-office-fixtures.py

@@ -0,0 +1,35 @@
+#!/usr/bin/env python3
+from pathlib import Path
+
+from docx import Document
+from openpyxl import Workbook
+from pptx import Presentation
+
+fixtures = Path(__file__).resolve().parent.parent / "fixtures"
+fixtures.mkdir(parents=True, exist_ok=True)
+
+# DOCX
+_doc = Document()
+_doc.add_heading("kkFileView E2E", level=1)
+_doc.add_paragraph("This is a DOCX fixture for Phase-2 E2E.")
+_doc.save(fixtures / "sample.docx")
+
+# XLSX
+_wb = Workbook()
+_ws = _wb.active
+_ws.title = "Sheet1"
+_ws["A1"] = "name"
+_ws["B1"] = "value"
+_ws["A2"] = "kkFileView"
+_ws["B2"] = 2
+_wb.save(fixtures / "sample.xlsx")
+
+# PPTX
+_prs = Presentation()
+slide_layout = _prs.slide_layouts[1]
+slide = _prs.slides.add_slide(slide_layout)
+slide.shapes.title.text = "kkFileView E2E"
+slide.placeholders[1].text = "This is a PPTX fixture for Phase-2 E2E."
+_prs.save(fixtures / "sample.pptx")
+
+print("office fixtures generated in", fixtures)