fix(dash): fix hardcoded paths and refactor duplicate model functions

[harsshks]

Summary

Fixes #76 — extends the approach proposed in #77 with additional code quality improvements.

Problem

dash.py contained hardcoded Windows-absolute paths that made the dashboard unusable on any machine other than the original developer's.

Changes Made

🐛 Bug Fix

• Replaced hardcoded C:\Users\SITAM MEUR\... paths with pathlib.Path(__file__).resolve().parent — anchored to the script file itself, so it works on Windows, Linux, and macOS regardless of the working directory

🛡️ Better Error Handling

• Added a directory existence check (data_dir.exists()) with st.error() + st.stop() before os.listdir() — gives a clear, actionable message instead of a bare crash
• Added st.stop() after FileNotFoundError on CSV load (prevents further rendering with no data)
• Added st.success("Data loaded successfully!") for positive feedback

♻️ Refactor (DRY)

• Merged model_for_mouse_x() and model_for_mouse_y() (~120 lines each, nearly identical) into a single evaluate_models(X, Y, axis_label, models, model_names) function — removes ~85 lines of duplicated logic

🔒 Reproducibility

• Added random_state=42 to train_test_split for consistent results across runs

🐛 Edge Case Fix

• Added division-by-zero guard in radar chart metric normalization

Related

• Fixes [BUG] : Fix hardcoded file paths in dash.py to make dashboard portable across systems #76
• See also: Fix hardcoded paths in dash.py for cross-platform compatibility #77 (earlier fix for the same issue)