Fix pt_dx.csv URI bug in rwd-lineage.xml and update .gitignore

- Correct 3 MapID source URIs (ICD10, TERM, DATE at RowIndex 1) that
  incorrectly pointed to notes.csv instead of pt_dx.csv
- Update Example1.xlsx to match corrected lineage mappings
- Extend .gitignore: exclude .DS_Store, **/tests/, Python bytecode,
  and pytest/coverage artifacts; untrack examples/example1/.DS_Store

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: tnagamine

.gitignore

@@ -1,2 +1,18 @@
 RWD Lineage Project Charter-v29-20260316_103831.docx
 examples/example1/generate_xml.py
+
+# macOS
+.DS_Store
+**/.DS_Store
+
+# Tests
+**/tests/
+
+# Python / pytest
+__pycache__/
+*.pyc
+*.pyo
+*.pyd
+.pytest_cache/
+.coverage
+htmlcov/

examples/example1/.DS_Store

@@ -262,7 +262,7 @@
     <Transformation type="DirectMap">Direct Map</Transformation>
     <Source>
       <Coordinate storage="Filesystem" structure="Tabular">
-        <URI>https://github.com/cdisc-org/DataExchange-RWD-Lineage/blob/main/examples/example1/data/source/notes.csv</URI>
+        <URI>https://github.com/cdisc-org/DataExchange-RWD-Lineage/blob/main/examples/example1/data/source/pt_dx.csv</URI>
         <RowIndex>1</RowIndex>
         <ColumnName>ICD10</ColumnName>
       </Coordinate>
@@ -279,7 +279,7 @@
     <Transformation type="DirectMap">Direct Map</Transformation>
     <Source>
       <Coordinate storage="Filesystem" structure="Tabular">
-        <URI>https://github.com/cdisc-org/DataExchange-RWD-Lineage/blob/main/examples/example1/data/source/notes.csv</URI>
+        <URI>https://github.com/cdisc-org/DataExchange-RWD-Lineage/blob/main/examples/example1/data/source/pt_dx.csv</URI>
         <RowIndex>1</RowIndex>
         <ColumnName>TERM</ColumnName>
       </Coordinate>
@@ -296,7 +296,7 @@
     <Transformation type="AfterIndexDate">After Index Date</Transformation>
     <Source>
       <Coordinate storage="Filesystem" structure="Tabular">
-        <URI>https://github.com/cdisc-org/DataExchange-RWD-Lineage/blob/main/examples/example1/data/source/notes.csv</URI>
+        <URI>https://github.com/cdisc-org/DataExchange-RWD-Lineage/blob/main/examples/example1/data/source/pt_dx.csv</URI>
         <RowIndex>1</RowIndex>
         <ColumnName>DATE</ColumnName>
       </Coordinate>