feat: add SQ8 vector quantization, lazy loading, and two-phase rerank to HNSW

- SQ8 scalar quantization (8-bit) for 4x vector storage reduction
- Lazy vector loading: evict float32 vectors after graph construction,
  load on-demand from storage via UnifiedCache
- Two-phase search: over-retrieve with SQ8 approximate distances,
  rerank top candidates with exact float32 distances
- Configuration surface: hnsw.quantization and hnsw.vectorStorage in BrainyConfig
- All features disabled by default (zero behavior change for existing users)
- 27 new tests covering quantization accuracy, lazy loading, reranking
- Remove GitHub Actions CI (build locally, cortex CI handles native builds)

.github/workflows/ci.yml

@@ -1,206 +0,0 @@
-name: CI
-
-on:
-  push:
-    branches: [main]
-  pull_request:
-    branches: [main]
-
-env:
-  NODE_VERSION: '20'
-  RUST_VERSION: 'stable'
-
-jobs:
-  # Build and test TypeScript/JavaScript
-  test-node:
-    name: Test (Node.js)
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-
-      - name: Setup Node.js
-        uses: actions/setup-node@v4
-        with:
-          node-version: ${{ env.NODE_VERSION }}
-          cache: 'npm'
-
-      - name: Install dependencies
-        run: npm ci
-
-      - name: Build TypeScript
-        run: npm run build
-
-      - name: Run unit tests
-        run: npm run test:unit
-
-      - name: Run integration tests
-        run: npm run test:integration
-
-  # Build and test with Bun
-  test-bun:
-    name: Test (Bun)
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-
-      - name: Setup Bun
-        uses: oven-sh/setup-bun@v2
-        with:
-          bun-version: latest
-
-      - name: Setup Node.js (for npm compatibility)
-        uses: actions/setup-node@v4
-        with:
-          node-version: ${{ env.NODE_VERSION }}
-          cache: 'npm'
-
-      - name: Install dependencies
-        run: npm ci
-
-      - name: Build TypeScript
-        run: npm run build
-
-      - name: Run Bun tests
-        run: npm run test:bun
-
-  # Build Candle WASM (if Rust source changed)
-  build-candle-wasm:
-    name: Build Candle WASM
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-
-      - name: Setup Rust
-        uses: dtolnay/rust-action@stable
-        with:
-          toolchain: ${{ env.RUST_VERSION }}
-          targets: wasm32-unknown-unknown
-
-      - name: Install wasm-pack
-        run: cargo install wasm-pack
-
-      - name: Cache Cargo registry
-        uses: actions/cache@v4
-        with:
-          path: |
-            ~/.cargo/registry
-            ~/.cargo/git
-            src/embeddings/candle-wasm/target
-          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
-
-      - name: Build WASM
-        run: |
-          cd src/embeddings/candle-wasm
-          wasm-pack build --target web --release
-
-      - name: Upload WASM artifacts
-        uses: actions/upload-artifact@v4
-        with:
-          name: candle-wasm
-          path: src/embeddings/wasm/pkg/
-          retention-days: 7
-
-  # Test Bun compile (standalone binary)
-  test-bun-compile:
-    name: Test Bun Compile
-    runs-on: ubuntu-latest
-    needs: [build-candle-wasm]
-    steps:
-      - uses: actions/checkout@v4
-
-      - name: Setup Bun
-        uses: oven-sh/setup-bun@v2
-        with:
-          bun-version: latest
-
-      - name: Setup Node.js
-        uses: actions/setup-node@v4
-        with:
-          node-version: ${{ env.NODE_VERSION }}
-          cache: 'npm'
-
-      - name: Download WASM artifacts
-        uses: actions/download-artifact@v4
-        with:
-          name: candle-wasm
-          path: src/embeddings/wasm/pkg/
-
-      - name: Install dependencies
-        run: npm ci
-
-      - name: Build TypeScript
-        run: npm run build
-
-      - name: Test Bun compile
-        run: |
-          # Create a test script
-          cat > /tmp/test-compile.ts << 'EOF'
-          import { Brainy } from './dist/index.js'
-
-          const brainy = new Brainy()
-          await brainy.init()
-          console.log('Brainy initialized!')
-
-          const embedding = await brainy.embed('Hello world')
-          console.log(`Embedding dimension: ${embedding.length}`)
-
-          if (embedding.length !== 384) {
-            throw new Error('Expected 384-dimensional embedding')
-          }
-
-          console.log('Test passed!')
-          EOF
-
-          # Compile to standalone binary
-          bun build --compile /tmp/test-compile.ts --outfile /tmp/brainy-test
-
-          # Run the compiled binary
-          /tmp/brainy-test
-
-  # Lint and type check
-  lint:
-    name: Lint & Type Check
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-
-      - name: Setup Node.js
-        uses: actions/setup-node@v4
-        with:
-          node-version: ${{ env.NODE_VERSION }}
-          cache: 'npm'
-
-      - name: Install dependencies
-        run: npm ci
-
-      - name: Type check
-        run: npm run typecheck
-
-      - name: Lint
-        run: npm run lint
-
-  # License check
-  license-check:
-    name: License Check
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-
-      - name: Setup Node.js
-        uses: actions/setup-node@v4
-        with:
-          node-version: ${{ env.NODE_VERSION }}
-          cache: 'npm'
-
-      - name: Install dependencies
-        run: npm ci
-
-      - name: Check licenses
-        run: |
-          # Install license checker
-          npm install -g license-checker
-
-          # Check for problematic licenses
-          license-checker --production --excludePrivatePackages \
-            --failOn 'GPL;LGPL;AGPL;SSPL' \
-            --summary