[AI] Expand Test Coverage - eldritch/lexer

[KCarretto]

This PR expands the test coverage for the eldritch-core lexer by adding a new test file lexer_new_coverage.rs. It targets edge cases such as complex f-strings, compound operators, and raw string escapes. The tests confirm the current behavior of the lexer, ensuring stability and preventing regressions. All tests have been verified to pass consistently.

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PR created automatically by Jules for task 3481646345893092555 started by @KCarretto

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[github-actions]

Summary

Tests 📝	Passed ✅	Failed ❌	Skipped ⏭️	Other ❓	Flaky 🍂	Duration ⏱️
2591    ±0	2591    ±0	0    ±0	0    ±0	0    ±0	0    ±0	1ms    ±0

Previous Results

Build 🏗️	Result 🧪	Tests 📝	Passed ✅	Failed ❌	Skipped ⏭️	Other ❓	Flaky 🍂	Duration ⏱️
#904	✅	2591	2591	0	0	0	0	20.5s

Insights

Average Tests per Run	Total Flaky Tests	Total Failed	Slowest Test (p95)
2591	0	0	5.2s

Slowest Tests

Test 📝	Results 📊	Duration (avg) ⏱️	Duration (p95) ⏱️
eldritch-libsys: std::dll_inject_impl::tests::test_dll_inject_simple	1	5.2s	5.2s
imix::bin/imix: install::tests::test_install_execution	3	1.2s	3.4s
imix::bin/imix: install::tests::test_install_execution	3	1.2s	3.4s
imix::bin/imix: install::tests::test_install_execution	3	1.2s	3.4s
imix::bin/imix: tests::task_tests::test_task_streaming_output	3	3.0s	3.1s
imix::bin/imix: tests::task_tests::test_task_streaming_output	3	3.0s	3.1s
imix::bin/imix: tests::task_tests::test_task_streaming_output	3	3.0s	3.1s
imix::bin/imix: tests::task_tests::test_task_streaming_error	3	3.0s	3.0s
imix::bin/imix: tests::task_tests::test_task_streaming_error	3	3.0s	3.0s
imix::bin/imix: tests::task_tests::test_task_streaming_error	3	3.0s	3.0s

_{🎉 No failed tests in this run. | 🍂 No flaky tests in this run.}

Github Test Reporter by CTRF 💚