test: 🚨 update tests for truncated multiline.txt

test(tests/examples/multiline.txt): 🚨 trim sample file to 10 lines to match new behavior
test(tests/integration_tests.rs): 🚨 adjust line ranges and expected outputs for 10-line sample; add multi-range context test

tests/examples/multiline.txt

@@ -8,13 +8,3 @@ line 7
 line 8
 line 9
 line 10
-line 11
-line 12
-line 13
-line 14
-line 15
-line 16
-line 17
-line 18
-line 19
-line 20