feat: add Streamlit dashboard for FYP showcase and viva

Five-tab production dashboard importing real project modules:

1. System overview -- research timeline, architecture diagram, metrics
2. Live anomaly detection -- scenario generation via ProposerAgent,
   evaluation through HybridVerifierAgent with per-layer score breakdown
3. Grid topology -- SSEN graph visualization with cascade injection
   using GraphAwareProposer and 2-hop BFS propagation
4. Evaluation results -- ROC-AUC comparison, ablation table, early-exit
   sweep chart, significance tests, voltage debugging narrative
5. Self-play training -- live SelfPlayTrainer episodes with reward and
   loss charts

Design: clean academic aesthetic (navy/teal/steel palette), no emojis,
plotly_white charts, system fonts. All data from real modules.

Run with: PYTHONPATH=src streamlit run app.py

Author: vmehtacode