Add comprehensive project README

README.md - Complete project index and navigation:

Structure:
- Quick links (decision makers, developers, architects, contributors)
- What is BITE/PANCAKE (problem, solution, innovations)
- Documentation map (13 documents organized by audience)
- Quick start guide (5-minute setup)
- Key features (production-ready, economically viable, technically sound)
- Contributing guide (developers, researchers, organizations)
- Project status (current state, milestones, risk assessment)
- Use cases (field scout, sensor network, vendor integration)
- Contact & resources
- License & governance (Apache 2.0, AgStack)
- Vision (2025-2030)

Documentation Organization:
1. Getting Started (3 docs): Executive summary, roadmap, POC setup
2. Core Specifications (5 docs): BITE, PANCAKE, TAP, SIRUP, SIP
3. Configuration (2 docs): Config reference, governance
4. Evaluation (4 docs): POC demo, critical review, whitepaper, delivery
5. Legacy (1 dir): Original Flask MVP (archived)

Quick Start:
- Prerequisites: Python 3.11+, PostgreSQL 15+
- Setup: 5 commands (clone, install, createdb, export, jupyter)
- Expected output: Working demo with real data

Key Metrics:
- Economics: ---3K (vs 2.5K-230K traditional, 99% savings)
- Performance: 10,000 writes/sec, <10ms queries
- Status: 8.5/10 launch-ready

Use Cases:
1. Field scout observation → AI query
2. Sensor network (100 sensors) → dashboard
3. Vendor integration (Planet satellite) → automated BITEs

Vision: "Agricultural data as interoperable as email, as queryable
as Google, and as open as Linux."

Target: 100,000 farms by 2030, global standard status.

Author: sumerjohal