V1.0: Class 1 fax — real-world 4-page send to external number confirmed

Core features:
- Class 1 T.30 protocol: full send/receive implementation
- HDLC: DLE-stuffing, FCS strip, USR5637 bit-reversal handling
- T.4 MH encoder/decoder (1728px A4 standard)
- Document pipeline: PDF (Ghostscript), PNG, TIFF input
- Width clamping: US Letter 1734px → 1728px fax standard
- Cover page: CJK rasterization (TW/CN/JP/EN), TIFF + HTML output
- OCR verification: Tesseract 5 with eng+chi_tra, CJK space-tolerant
- API server (axum): health, send, jobs, cover, retry, cancel
- Background worker: auto-poll queue, speed fallback, retry policy
- Modem detection, pool management

Real-world test results (2026-07-23):
- V90 → 25153038: 4 pages, V.17 12000 bps, 2:33 ✅
- USR5637 → 25153038: 4 pages, V.17 12000 bps, 2:26 ✅
- Both faxes confirmed received on remote machine

Tested: loopback (100% pixel match), multi-page, all input formats,
cover pages, OCR verify, API endpoints, worker processing.
13 unit tests pass, 0 new clippy warnings.

deployment/install.sh

@@ -0,0 +1,64 @@
+#!/bin/bash
+# Telfax Enterprise Fax Server Installation Script
+#
+# Usage: sudo ./install.sh
+
+set -e
+
+INSTALL_DIR="/opt/telfax"
+DATA_DIR="/var/lib/telfax"
+LOG_DIR="/var/log/telfax"
+CONFIG_FILE="$INSTALL_DIR/config.toml"
+
+echo "=== Telfax Enterprise Fax Server Installation ==="
+
+# Create user and group
+echo "Creating telfax user..."
+if ! id -u telfax &>/dev/null; then
+    useradd -r -s /bin/false telfax
+fi
+
+# Create directories
+echo "Creating directories..."
+mkdir -p "$INSTALL_DIR/bin"
+mkdir -p "$DATA_DIR"
+mkdir -p "$LOG_DIR"
+
+# Build the binary
+echo "Building telfax..."
+cd "$(dirname "$0")/.."
+cargo build --release
+cp target/release/telfax "$INSTALL_DIR/bin/"
+
+# Copy default config if not exists
+if [ ! -f "$CONFIG_FILE" ]; then
+    echo "Copying default configuration..."
+    cp deployment/config.toml "$CONFIG_FILE"
+    echo "IMPORTANT: Edit $CONFIG_FILE and set your authentication tokens!"
+fi
+
+# Install systemd service
+echo "Installing systemd service..."
+cp deployment/telfax.service /etc/systemd/system/
+systemctl daemon-reload
+
+# Set permissions
+echo "Setting permissions..."
+chown -R telfax:telfax "$INSTALL_DIR"
+chown -R telfax:telfax "$DATA_DIR"
+chown -R telfax:telfax "$LOG_DIR"
+chmod 600 "$CONFIG_FILE"
+
+echo ""
+echo "=== Installation Complete ==="
+echo ""
+echo "Configuration file: $CONFIG_FILE"
+echo "Data directory:     $DATA_DIR"
+echo "Log directory:      $LOG_DIR"
+echo ""
+echo "Next steps:"
+echo "  1. Edit $CONFIG_FILE and configure your modems and auth tokens"
+echo "  2. systemctl enable telfax"
+echo "  3. systemctl start telfax"
+echo "  4. journalctl -u telfax -f  # View logs"
+echo ""