fix(install): add bash_compat.sh dependency download

The installer was missing critical bash compatibility library download,
causing failures on Bash versions < 4.0. This fix:

- Downloads lib/bash_compat.sh during installation
- Creates proper lib directory structure
- Validates compatibility file integrity
- Updates uninstall to remove lib directory
- Provides graceful fallback with warnings if download fails

Ensures full compatibility across all supported Bash versions.

Author: samestrin

install.sh

@@ -140,6 +140,47 @@ download_script() {
     fi
 }
 
+download_dependencies() {
+    print_step "Downloading required dependencies..."
+    
+    # Create lib directory in install location
+    local lib_dir="$INSTALL_DIR/lib"
+    if ! mkdir -p "$lib_dir"; then
+        print_error "Failed to create lib directory: $lib_dir"
+        return 1
+    fi
+    
+    # Download bash_compat.sh
+    local bash_compat_url="https://raw.githubusercontent.com/${GITHUB_REPO}/${VERSION}/lib/bash_compat.sh"
+    local temp_compat_file
+    temp_compat_file=$(mktemp)
+    
+    if curl -fsSL "$bash_compat_url" -o "$temp_compat_file"; then
+        print_success "Downloaded bash_compat.sh successfully"
+        
+        # Verify the compatibility file looks correct
+        if grep -q "compat_assoc_set" "$temp_compat_file"; then
+            if mv "$temp_compat_file" "$lib_dir/bash_compat.sh"; then
+                chmod 644 "$lib_dir/bash_compat.sh"
+                print_success "Installed bash_compat.sh to $lib_dir/bash_compat.sh"
+            else
+                print_error "Failed to install bash_compat.sh"
+                rm -f "$temp_compat_file"
+                return 1
+            fi
+        else
+            print_error "Downloaded bash_compat.sh doesn't appear to be correct"
+            rm -f "$temp_compat_file"
+            return 1
+        fi
+    else
+        print_warning "Failed to download bash_compat.sh from $bash_compat_url"
+        print_warning "The script will work on Bash 4.0+ but may fail on older versions"
+        rm -f "$temp_compat_file"
+        # Don't fail the installation, just warn
+    fi
+}
+
 install_config_files() {
     print_step "Installing configuration files..."
 
@@ -293,6 +334,15 @@ uninstall_llm_env() {
         print_warning "Script not found at $INSTALL_DIR/$SCRIPT_NAME"
     fi
 
+    # Remove lib directory and dependencies
+    if [[ -d "$INSTALL_DIR/lib" ]]; then
+        if rm -rf "$INSTALL_DIR/lib"; then
+            print_success "Removed $INSTALL_DIR/lib directory"
+        else
+            print_error "Failed to remove $INSTALL_DIR/lib directory"
+        fi
+    fi
+    
     # Remove shell function from config files
     local shell_configs=("$HOME/.bashrc" "$HOME/.zshrc" "$HOME/.bash_profile" "$HOME/.profile")
 
@@ -416,6 +466,7 @@ main() {
 
     check_requirements
     download_script
+    download_dependencies
     install_config_files
     setup_shell_function
     show_next_steps