fix: improve TUI layout responsiveness for large host lists

This commit adds comprehensive support for SSH Include directives, 
allowing users to organize SSH configurations across multiple files.

Features:
- Support for Include directives with glob patterns (e.g., Include config.d/*)
- Circular include detection to prevent infinite recursion
- Graceful handling of missing include files
- Wildcard host filtering (ignores Host * patterns)
- Tilde expansion for home directory paths
- Relative path resolution from config file directory

The implementation maintains backward compatibility and includes 
comprehensive test coverage for all edge cases.

Thanks to @yimeng for this excellent contribution!

internal/config/ssh.go

@@ -96,25 +96,45 @@ func ParseSSHConfig() ([]SSHHost, error) {
 
 // ParseSSHConfigFile parses a specific SSH config file and returns the list of hosts
 func ParseSSHConfigFile(configPath string) ([]SSHHost, error) {
+	return parseSSHConfigFileWithProcessedFiles(configPath, make(map[string]bool))
+}
+
+// parseSSHConfigFileWithProcessedFiles parses SSH config with include support
+func parseSSHConfigFileWithProcessedFiles(configPath string, processedFiles map[string]bool) ([]SSHHost, error) {
+	// Resolve absolute path to prevent infinite recursion
+	absPath, err := filepath.Abs(configPath)
+	if err != nil {
+		return nil, fmt.Errorf("failed to resolve absolute path for %s: %w", configPath, err)
+	}
+
+	// Check for circular includes
+	if processedFiles[absPath] {
+		return []SSHHost{}, nil // Skip already processed files silently
+	}
+	processedFiles[absPath] = true
+
 	// Check if the file exists, otherwise create it (and the parent directory if needed)
 	if _, err := os.Stat(configPath); os.IsNotExist(err) {
-		// Ensure .ssh directory exists with proper permissions
-		if err := ensureSSHDirectory(); err != nil {
-			return nil, fmt.Errorf("failed to create .ssh directory: %w", err)
+		// Only create the main config file, not included files
+		if absPath == getMainConfigPath() {
+			// Ensure .ssh directory exists with proper permissions
+			if err := ensureSSHDirectory(); err != nil {
+				return nil, fmt.Errorf("failed to create .ssh directory: %w", err)
+			}
+
+			file, err := os.OpenFile(configPath, os.O_CREATE|os.O_WRONLY, 0600)
+			if err != nil {
+				return nil, fmt.Errorf("failed to create SSH config file: %w", err)
+			}
+			file.Close()
+
+			// Set secure permissions on the config file
+			if err := SetSecureFilePermissions(configPath); err != nil {
+				return nil, fmt.Errorf("failed to set secure permissions: %w", err)
+			}
 		}
 
-		file, err := os.OpenFile(configPath, os.O_CREATE|os.O_WRONLY, 0600)
-		if err != nil {
-			return nil, fmt.Errorf("failed to create SSH config file: %w", err)
-		}
-		file.Close()
-
-		// Set secure permissions on the config file
-		if err := SetSecureFilePermissions(configPath); err != nil {
-			return nil, fmt.Errorf("failed to set secure permissions: %w", err)
-		}
-
-		// File created, return empty host list
+		// File doesn't exist, return empty host list
 		return []SSHHost{}, nil
 	}
 
@@ -168,11 +188,25 @@ func ParseSSHConfigFile(configPath string) ([]SSHHost, error) {
 		value := strings.Join(parts[1:], " ")
 
 		switch key {
+		case "include":
+			// Handle Include directive
+			includeHosts, err := processIncludeDirective(value, configPath, processedFiles)
+			if err != nil {
+				// Don't fail the entire parse if include fails, just skip it
+				continue
+			}
+			hosts = append(hosts, includeHosts...)
 		case "host":
 			// New host, save previous one if it exists
 			if currentHost != nil {
 				hosts = append(hosts, *currentHost)
 			}
+			// Skip hosts with wildcards (*, ?) as they are typically patterns, not actual hosts
+			if strings.ContainsAny(value, "*?") {
+				currentHost = nil
+				pendingTags = nil
+				continue
+			}
 			// Create new host
 			currentHost = &SSHHost{
 				Name: value,
@@ -222,6 +256,55 @@ func ParseSSHConfigFile(configPath string) ([]SSHHost, error) {
 	return hosts, scanner.Err()
 }
 
+// processIncludeDirective processes an Include directive and returns hosts from included files
+func processIncludeDirective(pattern string, baseConfigPath string, processedFiles map[string]bool) ([]SSHHost, error) {
+	// Expand tilde to home directory
+	if strings.HasPrefix(pattern, "~") {
+		homeDir, err := os.UserHomeDir()
+		if err != nil {
+			return nil, fmt.Errorf("failed to get home directory: %w", err)
+		}
+		pattern = filepath.Join(homeDir, pattern[1:])
+	}
+
+	// If pattern is not absolute, make it relative to the base config directory
+	if !filepath.IsAbs(pattern) {
+		baseDir := filepath.Dir(baseConfigPath)
+		pattern = filepath.Join(baseDir, pattern)
+	}
+
+	// Use glob to find matching files
+	matches, err := filepath.Glob(pattern)
+	if err != nil {
+		return nil, fmt.Errorf("failed to glob pattern %s: %w", pattern, err)
+	}
+
+	var allHosts []SSHHost
+	for _, match := range matches {
+		// Skip directories
+		if info, err := os.Stat(match); err == nil && info.IsDir() {
+			continue
+		}
+
+		// Recursively parse the included file
+		hosts, err := parseSSHConfigFileWithProcessedFiles(match, processedFiles)
+		if err != nil {
+			// Skip files that can't be parsed rather than failing completely
+			continue
+		}
+		allHosts = append(allHosts, hosts...)
+	}
+
+	return allHosts, nil
+}
+
+// getMainConfigPath returns the main SSH config path for comparison
+func getMainConfigPath() string {
+	configPath, _ := GetDefaultSSHConfigPath()
+	absPath, _ := filepath.Abs(configPath)
+	return absPath
+}
+
 // AddSSHHost adds a new SSH host to the config file
 func AddSSHHost(host SSHHost) error {
 	configPath, err := GetDefaultSSHConfigPath()

internal/config/ssh_test.go

@@ -1,6 +1,7 @@
 package config
 
 import (
+	"os"
 	"path/filepath"
 	"runtime"
 	"strings"
@@ -71,3 +72,296 @@ func TestEnsureSSHDirectory(t *testing.T) {
 		t.Fatalf("ensureSSHDirectory() error = %v", err)
 	}
 }
+
+func TestParseSSHConfigWithInclude(t *testing.T) {
+	// Create temporary directory for test files
+	tempDir := t.TempDir()
+	
+	// Create main config file
+	mainConfig := filepath.Join(tempDir, "config")
+	mainConfigContent := `Host main-host
+    HostName example.com
+    User mainuser
+
+Include included.conf
+Include subdir/*
+
+Host another-host
+    HostName another.example.com
+    User anotheruser
+`
+	
+	err := os.WriteFile(mainConfig, []byte(mainConfigContent), 0600)
+	if err != nil {
+		t.Fatalf("Failed to create main config: %v", err)
+	}
+
+	// Create included file
+	includedConfig := filepath.Join(tempDir, "included.conf")
+	includedConfigContent := `Host included-host
+    HostName included.example.com
+    User includeduser
+    Port 2222
+`
+	
+	err = os.WriteFile(includedConfig, []byte(includedConfigContent), 0600)
+	if err != nil {
+		t.Fatalf("Failed to create included config: %v", err)
+	}
+
+	// Create subdirectory with another config file
+	subDir := filepath.Join(tempDir, "subdir")
+	err = os.MkdirAll(subDir, 0700)
+	if err != nil {
+		t.Fatalf("Failed to create subdir: %v", err)
+	}
+
+	subConfig := filepath.Join(subDir, "sub.conf")
+	subConfigContent := `Host sub-host
+    HostName sub.example.com
+    User subuser
+    IdentityFile ~/.ssh/sub_key
+`
+	
+	err = os.WriteFile(subConfig, []byte(subConfigContent), 0600)
+	if err != nil {
+		t.Fatalf("Failed to create sub config: %v", err)
+	}
+
+	// Parse the main config file
+	hosts, err := ParseSSHConfigFile(mainConfig)
+	if err != nil {
+		t.Fatalf("ParseSSHConfigFile() error = %v", err)
+	}
+
+	// Check that we got all expected hosts
+	expectedHosts := map[string]struct{}{
+		"main-host":     {},
+		"included-host": {},
+		"sub-host":      {},
+		"another-host":  {},
+	}
+
+	if len(hosts) != len(expectedHosts) {
+		t.Errorf("Expected %d hosts, got %d", len(expectedHosts), len(hosts))
+	}
+
+	for _, host := range hosts {
+		if _, exists := expectedHosts[host.Name]; !exists {
+			t.Errorf("Unexpected host found: %s", host.Name)
+		}
+		delete(expectedHosts, host.Name)
+
+		// Validate specific host properties
+		switch host.Name {
+		case "main-host":
+			if host.Hostname != "example.com" || host.User != "mainuser" {
+				t.Errorf("main-host properties incorrect: hostname=%s, user=%s", host.Hostname, host.User)
+			}
+		case "included-host":
+			if host.Hostname != "included.example.com" || host.User != "includeduser" || host.Port != "2222" {
+				t.Errorf("included-host properties incorrect: hostname=%s, user=%s, port=%s", host.Hostname, host.User, host.Port)
+			}
+		case "sub-host":
+			if host.Hostname != "sub.example.com" || host.User != "subuser" || host.Identity != "~/.ssh/sub_key" {
+				t.Errorf("sub-host properties incorrect: hostname=%s, user=%s, identity=%s", host.Hostname, host.User, host.Identity)
+			}
+		case "another-host":
+			if host.Hostname != "another.example.com" || host.User != "anotheruser" {
+				t.Errorf("another-host properties incorrect: hostname=%s, user=%s", host.Hostname, host.User)
+			}
+		}
+	}
+
+	// Check that all expected hosts were found
+	if len(expectedHosts) > 0 {
+		var missing []string
+		for host := range expectedHosts {
+			missing = append(missing, host)
+		}
+		t.Errorf("Missing hosts: %v", missing)
+	}
+}
+
+func TestParseSSHConfigWithCircularInclude(t *testing.T) {
+	// Create temporary directory for test files
+	tempDir := t.TempDir()
+	
+	// Create config1 that includes config2
+	config1 := filepath.Join(tempDir, "config1")
+	config1Content := `Host host1
+    HostName example1.com
+
+Include config2
+`
+	
+	err := os.WriteFile(config1, []byte(config1Content), 0600)
+	if err != nil {
+		t.Fatalf("Failed to create config1: %v", err)
+	}
+
+	// Create config2 that includes config1 (circular)
+	config2 := filepath.Join(tempDir, "config2")
+	config2Content := `Host host2
+    HostName example2.com
+
+Include config1
+`
+	
+	err = os.WriteFile(config2, []byte(config2Content), 0600)
+	if err != nil {
+		t.Fatalf("Failed to create config2: %v", err)
+	}
+
+	// Parse the config file - should not cause infinite recursion
+	hosts, err := ParseSSHConfigFile(config1)
+	if err != nil {
+		t.Fatalf("ParseSSHConfigFile() error = %v", err)
+	}
+
+	// Should get both hosts exactly once
+	expectedHosts := map[string]bool{
+		"host1": false,
+		"host2": false,
+	}
+
+	for _, host := range hosts {
+		if _, exists := expectedHosts[host.Name]; !exists {
+			t.Errorf("Unexpected host found: %s", host.Name)
+		} else {
+			if expectedHosts[host.Name] {
+				t.Errorf("Host %s found multiple times", host.Name)
+			}
+			expectedHosts[host.Name] = true
+		}
+	}
+
+	// Check all hosts were found
+	for hostName, found := range expectedHosts {
+		if !found {
+			t.Errorf("Host %s not found", hostName)
+		}
+	}
+}
+
+func TestParseSSHConfigWithNonExistentInclude(t *testing.T) {
+	// Create temporary directory for test files
+	tempDir := t.TempDir()
+	
+	// Create main config file with non-existent include
+	mainConfig := filepath.Join(tempDir, "config")
+	mainConfigContent := `Host main-host
+    HostName example.com
+
+Include non-existent-file.conf
+
+Host another-host
+    HostName another.example.com
+`
+	
+	err := os.WriteFile(mainConfig, []byte(mainConfigContent), 0600)
+	if err != nil {
+		t.Fatalf("Failed to create main config: %v", err)
+	}
+
+	// Parse should succeed and ignore the non-existent include
+	hosts, err := ParseSSHConfigFile(mainConfig)
+	if err != nil {
+		t.Fatalf("ParseSSHConfigFile() error = %v", err)
+	}
+
+	// Should get the hosts that exist, ignoring the failed include
+	if len(hosts) != 2 {
+		t.Errorf("Expected 2 hosts, got %d", len(hosts))
+	}
+
+	hostNames := make(map[string]bool)
+	for _, host := range hosts {
+		hostNames[host.Name] = true
+	}
+
+	if !hostNames["main-host"] || !hostNames["another-host"] {
+		t.Errorf("Expected main-host and another-host, got: %v", hostNames)
+	}
+}
+
+func TestParseSSHConfigWithWildcardHosts(t *testing.T) {
+	// Create temporary directory for test files
+	tempDir := t.TempDir()
+	
+	// Create config file with wildcard hosts
+	configFile := filepath.Join(tempDir, "config")
+	configContent := `# Wildcard patterns should be ignored
+Host *.example.com
+    User defaultuser
+    IdentityFile ~/.ssh/id_rsa
+
+Host server-*
+    Port 2222
+
+Host *
+    ServerAliveInterval 60
+
+# Real hosts should be included
+Host real-server
+    HostName real.example.com
+    User realuser
+
+Host another-real-server
+    HostName another.example.com
+    User anotheruser
+`
+	
+	err := os.WriteFile(configFile, []byte(configContent), 0600)
+	if err != nil {
+		t.Fatalf("Failed to create config: %v", err)
+	}
+
+	// Parse the config file
+	hosts, err := ParseSSHConfigFile(configFile)
+	if err != nil {
+		t.Fatalf("ParseSSHConfigFile() error = %v", err)
+	}
+
+	// Should only get real hosts, not wildcard patterns
+	expectedHosts := map[string]bool{
+		"real-server":         false,
+		"another-real-server": false,
+	}
+
+	if len(hosts) != len(expectedHosts) {
+		t.Errorf("Expected %d hosts, got %d", len(expectedHosts), len(hosts))
+		for _, host := range hosts {
+			t.Logf("Found host: %s", host.Name)
+		}
+	}
+
+	for _, host := range hosts {
+		if _, expected := expectedHosts[host.Name]; !expected {
+			t.Errorf("Unexpected host found: %s", host.Name)
+		} else {
+			expectedHosts[host.Name] = true
+		}
+	}
+
+	// Check that all expected hosts were found
+	for hostName, found := range expectedHosts {
+		if !found {
+			t.Errorf("Expected host %s not found", hostName)
+		}
+	}
+
+	// Verify host properties
+	for _, host := range hosts {
+		switch host.Name {
+		case "real-server":
+			if host.Hostname != "real.example.com" || host.User != "realuser" {
+				t.Errorf("real-server properties incorrect: hostname=%s, user=%s", host.Hostname, host.User)
+			}
+		case "another-real-server":
+			if host.Hostname != "another.example.com" || host.User != "anotheruser" {
+				t.Errorf("another-real-server properties incorrect: hostname=%s, user=%s", host.Hostname, host.User)
+			}
+		}
+	}
+}

internal/ui/table.go

@@ -142,22 +142,36 @@ func (m *Model) updateTableHeight() {
 		return
 	}
 
+	// Calculate dynamic table height based on terminal size
+	// Layout breakdown:
+	// - ASCII title: 5 lines (1 empty + 4 text lines)
+	// - Search bar: 1 line
+	// - Help text: 1 line
+	// - App margins/spacing: 3 lines
+	// - Safety margin: 3 lines (to ensure UI elements are always visible)
+	// Total reserved: 12 lines minimum to preserve essential UI elements
+	reservedHeight := 12
+	availableHeight := m.height - reservedHeight
 	hostCount := len(m.table.Rows())
 
-	// Calculate exactly what we need:
-	// 1 line for header + actual number of host rows + 1 extra line for better UX
-	tableHeight := 1 + hostCount + 1
-
-	// Set a reasonable maximum based on terminal height
-	// Leave space for: title (5) + search (1) + help (1) + margins (2) = 9 lines
-	// But be less conservative, use 7 lines instead of 9
-	maxPossibleHeight := m.height - 7
-	if maxPossibleHeight < 4 {
-		maxPossibleHeight = 4 // Minimum: header + 3 rows
+	// Minimum height should be at least 3 rows for basic usability
+	// Even in very small terminals, we want to show at least header + 2 hosts
+	minTableHeight := 4 // 1 header + 3 data rows minimum
+	maxTableHeight := availableHeight
+	if maxTableHeight < minTableHeight {
+		maxTableHeight = minTableHeight
 	}
 
-	if tableHeight > maxPossibleHeight {
-		tableHeight = maxPossibleHeight
+	tableHeight := 1 // header
+	dataRowsNeeded := hostCount
+	maxDataRows := maxTableHeight - 1 // subtract 1 for header
+
+	if dataRowsNeeded <= maxDataRows {
+		// We have enough space for all hosts
+		tableHeight += dataRowsNeeded
+	} else {
+		// We need to limit to available space
+		tableHeight += maxDataRows
 	}
 
 	// Update table height