test: 🚨 extend line-range tests

test(tests/examples/multiline.txt): 🚨 add lines 5-20 to sample file for expanded line-range tests
test(tests/integration_tests.rs): 🚨 update expected outputs and add comprehensive context and error tests for line-range feature

tests/examples/multiline.txt

@@ -2,3 +2,19 @@ line 1
 line 2
 line 3
 line 4
+line 5
+line 6
+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