fix(GH#1224): detect Docker Desktop bind mounts in WSL2 and disable WAL mode

Fixes stack overflow and database initialization failures when running bd on WSL2 with Docker Desktop bind mounts.

## Problem
The bd CLI crashed with stack overflow when running on WSL2 with repositories on Docker Desktop bind mounts (/mnt/wsl/docker-desktop-bind-mounts/...). SQLite WAL mode fails with 'locking protocol' error on these network filesystems.

## Solution
- Expand WAL mode detection to identify Docker bind mounts at /mnt/wsl/* (in addition to Windows paths at /mnt/[a-zA-Z]/)
- Fall back to DELETE journal mode on these problematic paths
- Add comprehensive unit tests for path detection

Fixes GH #1224, relates to GH #920

Co-authored-by: maphew <matt.wilkie@gmail.com>

test_wsl2_wal.sh

@@ -0,0 +1,44 @@
+#!/bin/bash
+# Test script to reproduce GH#1224 - SQLite WAL mode on WSL2 bind mounts
+
+set -e
+
+echo "=== Testing SQLite WAL mode on WSL2 bind mounts ==="
+
+# Check if we're in WSL2
+if ! grep -qi microsoft /proc/version; then
+    echo "Not running in WSL2, skipping test"
+    exit 0
+fi
+
+# Create test directory in different locations
+test_paths=(
+    "/tmp/beads-test-wal"                    # /tmp (Linux filesystem)
+    "/mnt/c/temp/beads-test-wal"             # Windows filesystem (if available)
+)
+
+# Add Docker Desktop bind mount if available
+if [ -d "/mnt/wsl" ]; then
+    test_paths+=("/mnt/wsl/beads-test-wal")  # Docker Desktop bind mount
+fi
+
+for test_path in "${test_paths[@]}"; do
+    echo ""
+    echo "Testing WAL mode at: $test_path"
+    
+    # Create directory
+    mkdir -p "$test_path"
+    
+    # Test with SQLite CLI
+    sqlite3 "$test_path/test.db" "PRAGMA journal_mode=WAL;" 2>&1 | head -1
+    
+    # Check if WAL was actually enabled
+    journal_mode=$(sqlite3 "$test_path/test.db" "PRAGMA journal_mode;" 2>&1 | head -1)
+    echo "Journal mode: $journal_mode"
+    
+    # Clean up
+    rm -rf "$test_path"
+done
+
+echo ""
+echo "=== Test complete ==="