Implement aios initial direction: AI-managed OS with shared memory

This commit implements the new direction for aios:
- AI conversation interface replaces traditional shell
- aigpt integration for shared memory across containers
- systemd-nspawn for environment isolation

Changes:
- Added aios-install.sh: Complete installer script
- Added cfg/mcp.json: MCP server configuration for aigpt
- Added cfg/config.toml: aios configuration with permission system
- Added cfg/nspawn/aios.nspawn: systemd-nspawn configuration
- Updated build.zsh: Integrated aigpt installation and setup
- Updated README.md: Documented new architecture and philosophy

Architecture:
User → AI Chat → Commands → Execution
         ↓
     aigpt (shared memory)
         ↓
  systemd-nspawn (isolated environment)

Philosophy:
Simply insert AI into existing flows (shell → AI chat)

aios-install.sh

@@ -0,0 +1,151 @@
+#!/bin/bash
+# aios installer - AI-managed OS with shared memory
+
+set -e
+
+AIOS_VERSION="0.1.0"
+AIOS_ROOT="/var/lib/machines/aios"
+AIOS_CONFIG="$HOME/.config/syui/ai"
+
+echo "=== aios installer v${AIOS_VERSION} ==="
+echo ""
+echo "aios = AI-managed OS with shared memory"
+echo "- Default interface: AI chat (not shell)"
+echo "- Shared memory: aigpt (SQLite)"
+echo "- Environment isolation: systemd-nspawn"
+echo ""
+
+# Check if running as root for container creation
+if [ "$EUID" -ne 0 ] && [ ! -d "$AIOS_ROOT" ]; then
+    echo "Note: Container creation requires root privileges"
+    echo "      User config will be created in: $AIOS_CONFIG"
+fi
+
+# 1. Create shared memory directory
+echo "[1/6] Creating shared memory directory..."
+mkdir -p "${AIOS_CONFIG}/gpt"
+chmod 700 "${AIOS_CONFIG}"
+echo "✓ Created: ${AIOS_CONFIG}"
+
+# 2. Download bootstrap container (if not exists)
+if [ ! -d "$AIOS_ROOT" ]; then
+    echo "[2/6] Downloading aios bootstrap container..."
+    if [ "$EUID" -eq 0 ]; then
+        mkdir -p /var/lib/machines
+        cd /var/lib/machines
+        curl -sL https://github.com/syui/aios/releases/download/latest/aios-bootstrap.tar.gz | tar xz
+        echo "✓ Bootstrap container extracted to: $AIOS_ROOT"
+    else
+        echo "⚠ Skipping (requires root)"
+    fi
+else
+    echo "[2/6] Bootstrap container already exists"
+fi
+
+# 3. Install aigpt (if not installed)
+if ! command -v aigpt &>/dev/null; then
+    echo "[3/6] Installing aigpt..."
+    if command -v cargo &>/dev/null; then
+        cd /tmp
+        git clone https://git.syui.ai/ai/gpt || git clone https://github.com/syui/aigpt
+        cd gpt 2>/dev/null || cd aigpt
+        cargo build --release
+
+        if [ "$EUID" -eq 0 ]; then
+            cp target/release/aigpt /usr/bin/
+        else
+            mkdir -p ~/.local/bin
+            cp target/release/aigpt ~/.local/bin/
+            echo "  Add to PATH: export PATH=\$HOME/.local/bin:\$PATH"
+        fi
+        echo "✓ aigpt installed"
+    else
+        echo "⚠ cargo not found. Install rust first:"
+        echo "    curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh"
+    fi
+else
+    echo "[3/6] aigpt already installed"
+fi
+
+# 4. Initialize aigpt database
+if [ ! -f "${AIOS_CONFIG}/gpt/memory.db" ]; then
+    echo "[4/6] Initializing aigpt database..."
+
+    # Start aigpt server temporarily to create DB
+    if command -v aigpt &>/dev/null; then
+        aigpt server --enable-layer4 &
+        AIGPT_PID=$!
+        sleep 2
+        kill $AIGPT_PID 2>/dev/null || true
+
+        # Enable WAL mode for concurrent access
+        if command -v sqlite3 &>/dev/null; then
+            sqlite3 "${AIOS_CONFIG}/gpt/memory.db" <<EOF
+PRAGMA journal_mode=WAL;
+PRAGMA synchronous=NORMAL;
+PRAGMA cache_size=-64000;
+EOF
+            echo "✓ Database initialized with WAL mode"
+        else
+            echo "⚠ sqlite3 not found, skipping WAL mode setup"
+        fi
+    else
+        echo "⚠ aigpt not available, skipping database init"
+    fi
+else
+    echo "[4/6] Database already exists"
+fi
+
+# 5. Install MCP configuration
+echo "[5/6] Installing MCP configuration..."
+cp cfg/mcp.json "${AIOS_CONFIG}/mcp.json"
+cp cfg/config.toml "${AIOS_CONFIG}/config.toml"
+echo "✓ Configuration files installed"
+
+# 6. Install systemd-nspawn configuration
+if [ "$EUID" -eq 0 ]; then
+    echo "[6/6] Installing systemd-nspawn configuration..."
+    mkdir -p /etc/systemd/nspawn
+
+    # Replace %h with actual home directory
+    sed "s|%h|$HOME|g" cfg/nspawn/aios.nspawn > /etc/systemd/nspawn/aios.nspawn
+
+    echo "✓ systemd-nspawn configuration installed"
+
+    # Enable and start container
+    echo ""
+    echo "Starting aios container..."
+    systemctl enable systemd-nspawn@aios
+    systemctl start systemd-nspawn@aios
+    echo "✓ aios container started"
+else
+    echo "[6/6] Skipping systemd setup (requires root)"
+fi
+
+echo ""
+echo "================================================"
+echo "✓ aios installation complete!"
+echo "================================================"
+echo ""
+
+if command -v aigpt &>/dev/null; then
+    echo "Next steps:"
+    echo ""
+    echo "  # Enter aios container:"
+    echo "  $ sudo machinectl shell aios"
+    echo ""
+    echo "  # Or start AI chat interface:"
+    echo "  $ aios shell"
+    echo ""
+else
+    echo "To complete installation:"
+    echo "  1. Install Rust: curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh"
+    echo "  2. Run this installer again: ./aios-install.sh"
+fi
+
+echo ""
+echo "Configuration:"
+echo "  Config dir: ${AIOS_CONFIG}"
+echo "  Memory DB:  ${AIOS_CONFIG}/gpt/memory.db"
+echo "  MCP config: ${AIOS_CONFIG}/mcp.json"
+echo ""