feat(import): Z-wafer CSV import button with result banner

- importZWaferCsv slot on FileBrowser — converts and adds to list
- SourcePanel: import icon button → FileDialog → importSummary banner
  (auto-dismisses after 5s, loads the converted file into streamController)
- wafer_map_item: showExtremes default → true

tests/test_file_browser.py

@@ -1,3 +1,4 @@
+import json
 from pathlib import Path
 
 from pygui.backend.data.file_browser import FileBrowser
@@ -15,6 +16,24 @@ def _write_csv(path, wafer_id="P00001"):
     )
 
 
+def _write_raw_zwafer_export(path, wafer_id="P00001", chamber="Chamber A", comments="test run"):
+    """A raw fixture-export CSV, as ZWaferParser/ImportZWaferCSV expect it:
+    row-indexed data rows (leading column dropped on import), unlike the
+    already-normalized `{serial}-{timestamp}.csv` files _write_csv produces."""
+    path.write_text(
+        f"Wafer ID={wafer_id}\n"
+        "Acquisition Date=03/26/2025\n"
+        f"Chamber={chamber}\n"
+        f"Comments={comments}\n"
+        "Label,1,2,3\n"
+        "X (mm),0,10,-10\n"
+        "Y (mm),10,-10,-10\n"
+        "data\n"
+        "0.0,149.0,148.5,150.6\n"
+        "1.0,149.2,148.7,150.9\n"
+    )
+
+
 def test_recorded_live_file_flagged_as_recording(qapp, tmp_path):
     """Files named live_<serial>_<timestamp>.csv (SessionController.startRecording)
     must be distinguishable in the browser from read-memory dumps."""
@@ -41,3 +60,103 @@ def test_set_current_directory_updates_dir_and_refreshes(qapp, tmp_path):
     assert browser.currentDirectory == str(tmp_path)
     assert len(browser.files) == 1
     assert Path(browser.files[0]["fileName"]).name == "P00003-20260706_143500.csv"
+
+
+def test_import_zwafer_csv_writes_normalized_file_and_sidecar(qapp, tmp_path):
+    """Mirrors C#'s ImportZWaferCSV (Form1.cs:1711): strip the leading row-index
+    column, rename to {serial}-{timestamp}.csv (no Z prefix — matches this app's
+    other write paths), write a metadata sidecar, and refresh the file list."""
+    source_dir = tmp_path / "incoming"
+    source_dir.mkdir()
+    source = source_dir / "raw_export.csv"
+    _write_raw_zwafer_export(source)
+
+    browser = FileBrowser()
+    browser._set_current_directory(tmp_path)
+
+    signals = []
+    browser.importFinished.connect(lambda path, message: signals.append((path, message)))
+    browser.importZWaferCsv(str(source))
+
+    new_path = tmp_path / "P00001-20250326_000000.csv"
+    assert new_path.exists()
+    assert new_path.read_text().splitlines() == [
+        "1,2,3",
+        "149.0,148.5,150.6",
+        "149.2,148.7,150.9",
+    ]
+
+    sidecar = json.loads((tmp_path / "P00001-20250326_000000.csv.json").read_text())
+    assert sidecar["wafer"] == "P00001"
+    assert sidecar["chamber"] == "Chamber A"
+    assert sidecar["notes"] == "test run"
+
+    assert len(signals) == 1
+    assert signals[0][0] == str(new_path)
+    assert any(Path(row["fileName"]).name == new_path.name for row in browser.files)
+
+
+def test_import_zwafer_csv_blocks_reimporting_same_source(qapp, tmp_path):
+    """Re-importing the identical source file must be blocked, not overwritten —
+    the output filename is derived from the source's own acquisition-date
+    header, so a second import of the same file collides on purpose."""
+    source_dir = tmp_path / "incoming"
+    source_dir.mkdir()
+    source = source_dir / "raw_export.csv"
+    _write_raw_zwafer_export(source)
+
+    browser = FileBrowser()
+    browser._set_current_directory(tmp_path)
+
+    signals = []
+    browser.importFinished.connect(lambda path, message: signals.append((path, message)))
+
+    browser.importZWaferCsv(str(source))
+    browser.importZWaferCsv(str(source))
+
+    assert len(signals) == 2
+    assert signals[1][0] == ""
+    assert "already" in signals[1][1].lower()
+
+
+def test_import_zwafer_csv_without_date_header_still_blocks_duplicate(qapp, tmp_path):
+    """No fallback to wall-clock time: a source missing 'Acquisition Date='
+    must still get a deterministic filename, so re-importing it a second
+    time is blocked instead of silently succeeding with a fresh timestamp."""
+    source_dir = tmp_path / "incoming"
+    source_dir.mkdir()
+    source = source_dir / "raw_export.csv"
+    source.write_text(
+        "Wafer ID=P00002\n"
+        "Label,1,2,3\n"
+        "X (mm),0,10,-10\n"
+        "Y (mm),10,-10,-10\n"
+        "data\n"
+        "0.0,149.0,148.5,150.6\n"
+    )
+
+    browser = FileBrowser()
+    browser._set_current_directory(tmp_path)
+
+    signals = []
+    browser.importFinished.connect(lambda path, message: signals.append((path, message)))
+
+    browser.importZWaferCsv(str(source))
+    browser.importZWaferCsv(str(source))
+
+    assert len(signals) == 2
+    assert signals[0][0] != ""  # first import succeeds
+    assert signals[1][0] == ""  # second is blocked
+    assert "already" in signals[1][1].lower()
+
+
+def test_import_zwafer_csv_reports_missing_source(qapp, tmp_path):
+    browser = FileBrowser()
+    browser._set_current_directory(tmp_path)
+
+    signals = []
+    browser.importFinished.connect(lambda path, message: signals.append((path, message)))
+    browser.importZWaferCsv(str(tmp_path / "missing.csv"))
+
+    assert len(signals) == 1
+    assert signals[0][0] == ""