Implement zero-config philosophy: Remove .env in favor of smart auto-detection

- Added CONFIGURATION.md explaining zero-config approach
- Created SmartModelLoader for intelligent model fetching
- Removed .env.example (configuration files are security theater)
- Models load from multiple sources automatically (local, CDN, cache)
- Credentials detected from secure OS keychains, not files

CONFIGURATION.md

@@ -0,0 +1,112 @@
+# 🚫 No Configuration Required
+
+Brainy follows a **zero-configuration philosophy**. We automatically detect and adapt to your environment.
+
+## How It Works
+
+### 🔐 API Keys & Secrets
+**Never put keys in files!** Brainy automatically detects credentials from:
+1. **System Keychains** - macOS Keychain, Windows Credential Manager, Linux Secret Service
+2. **Cloud IAM** - AWS IAM roles, Google Cloud Service Accounts, Azure Managed Identity  
+3. **Secure Prompts** - Asked once, stored securely (never in plaintext)
+
+```javascript
+// Just use brainy - it will find credentials securely
+const brain = new BrainyVectorDB()
+await brain.connect() // Auto-detects everything
+```
+
+### 🌍 Environment Detection
+Brainy automatically detects:
+- Browser vs Node.js vs Serverless
+- Available memory and CPU cores
+- Storage backends (filesystem, S3, browser storage)
+- Network endpoints and services
+
+### 🎯 Smart Defaults
+Based on your environment, Brainy automatically configures:
+- Memory limits (50% of available)
+- Cache sizes (adaptive to usage)
+- Batch sizes (based on latency)
+- Compression (when beneficial)
+
+## When You DO Need Configuration
+
+For advanced use cases only:
+
+### Secure Credential Storage
+
+```bash
+# macOS
+security add-generic-password -s brainy-api -a user -w YOUR_KEY
+
+# Linux
+secret-tool store --label="Brainy API" service brainy-api
+
+# Windows
+cmdkey /generic:brainy-api /user:user /pass:YOUR_KEY
+```
+
+### Programmatic Override
+
+```javascript
+const brain = new BrainyVectorDB({
+  // Only override if you know better than auto-detection
+  storage: 's3://my-bucket',
+  memory: '2GB'
+})
+```
+
+## Philosophy
+
+> "The best configuration is no configuration. Software should be smart enough to figure out what you need."
+
+Brainy detects, adapts, and optimizes automatically. If you find yourself needing configuration, we've failed - please open an issue!
+
+## Security Without .env
+
+Traditional `.env` files are security theater:
+- ❌ Get committed accidentally  
+- ❌ Sit in plaintext on disk
+- ❌ Copied around carelessly
+- ❌ Different for every environment
+
+Brainy's approach:
+- ✅ Never store secrets in files
+- ✅ Use OS-level secure storage
+- ✅ Detect cloud IAM automatically
+- ✅ Adapt to environment dynamically
+
+## Examples
+
+### Local Development
+```javascript
+const brain = new BrainyVectorDB()
+// Detects: Node.js, 16GB RAM, filesystem storage
+// Auto-configures: 8GB memory limit, disk-backed cache
+```
+
+### Browser
+```javascript
+const brain = new BrainyVectorDB()  
+// Detects: Browser, 4GB available, IndexedDB
+// Auto-configures: 2GB limit, OPFS storage, WebWorker processing
+```
+
+### AWS Lambda
+```javascript
+const brain = new BrainyVectorDB()
+// Detects: Lambda, 3GB RAM, S3 access
+// Auto-configures: 2.5GB limit, S3 storage, credential from IAM role
+```
+
+### Cloudflare Worker
+```javascript
+const brain = new BrainyVectorDB()
+// Detects: Worker, 128MB limit, KV available
+// Auto-configures: 100MB limit, KV storage, edge caching
+```
+
+## No Configuration Needed
+
+Just use Brainy. It figures out the rest.