⚡ Bolt: Optimize _safe_truncate string length check in TUI render loop

[omsingh02]

💡 What: Replaced the rich.text.Text instantiation with a built-in len(text) check in the _safe_truncate method of src/ui/tui.py.
🎯 Why: Creating a Text object solely to check the length of an unstyled string is computationally expensive and introduces a severe performance bottleneck inside the TUI's continuous render loop.
📊 Impact: Substantially reduces the overhead during each render cycle by bypassing object creation entirely, resulting in snappier TUI performance, especially when handling large song histories.
🔬 Measurement: Verify the speedup by running python -m src.main and observing smoother navigation and rendering, alongside verifying via pytest src/ and python -m compileall src/ that no regressions were introduced.

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PR created automatically by Jules for task 12037801514630474544 started by @omsingh02

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