feat: add Graph Synchronization Engine - autonomous Kuramoto oscillator simulation

Adds GraphSynchronizationEngine with 7 analysis engines:
1. Oscillator Initializer - random natural frequencies and phase assignment
2. Kuramoto Simulator - coupled oscillator dynamics via Euler integration
3. Order Parameter Tracker - global coherence r(t) trajectory
4. Critical Coupling Estimator - K_c detection via coupling sweep
5. Synchronization Barrier Detector - frequency outliers, bridge edges,
   articulation points, and isolated clusters
6. Desynchronizer Profiler - leave-one-out node impact analysis
7. Insight Generator - autonomous sync dynamics recommendations

Features:
- Full Kuramoto model: dθ/dt = ω + (K/deg) Σ sin(θ_j - θ_i)
- Order parameter r = |1/N Σ exp(iθ)| tracking
- Bridge/articulation point detection via Tarjan DFS
- Connected component analysis for disconnected graphs
- Health scoring 0-100 with 5 tiers
- Interactive HTML dashboard with trajectory and coupling charts
- Builder-style configuration (coupling, time steps, seed)

Includes 85 JUnit tests covering empty/single/triangle/star/path/
complete/grid/disconnected/barbell/ring topologies, deterministic
seeding, barrier detection, desynchronizer profiling, and HTML export.

Author: sauravbhattacharya001