Redefine README around new product philosophy

Dhee is self-evolving memory for every AI agent. Three pillars:
- Reduces tokens (90%+ per turn)
- Perfect recall, years in (decay + promotion + self-tuning retrieval)
- Future-proofs fat skills (CLAUDE.md, AGENTS.md, GBrain)

Rewrites the value prop upfront, leads with the #1 LongMemEval result,
adds a vs-alternatives table (vs Mem0/Letta/MemPalace/agentmemory),
dedicated sections on self-evolution and long-term recall.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: Ashish-dwi99