feat: add 5 major SSH/Terminal features for v0.14.0

## 🚀 New Features

### 1. SSH Agent Forwarding
- Auto-detect SSH agent socket (SSH_AUTH_SOCK, macOS/Linux common paths)
- Forward local SSH agent to remote hosts via jump hosts
- Per-connection setting in Advanced tab

### 2. Zmodem File Transfer (lrzsz)
- Send/receive files over terminal using rz/sz commands
- Automatic detection of Zmodem sequences in terminal stream
- Full IPC handlers for file transfer workflow
- React hook `useZmodem()` for UI integration
- Requires lrzsz installed on remote host

### 3. True Color (24-bit) & Sixel Graphics
- Enable 24-bit color support in terminal
- Sixel graphics support for displaying images in terminal
- Per-connection setting: xterm-256color-tc-sixel terminal type

### 4. SSH ProxyJump Chain Support
- Added `proxyJumpChain` field for future multi-hop SSH chains
- Infrastructure ready for complex SSH routing scenarios

### 5. Keep-Alive & Anti-Idle
- **SSH Keep-Alive**: Automatic ping packets at configurable intervals
- **Anti-Idle**: Send null bytes or custom strings to prevent timeout
- Configurable interval, count max, and idle string per connection

## 🔧 Technical Changes

### Database Schema (SQLite)
- Added 11 new columns to `connections` table:
  - `agent_forwarding`, `keepalive_interval`, `keepalive_count_max`
  - `ready_timeout`, `proxy_jump_chain`
  - `anti_idle`, `anti_idle_interval`, `anti_idle_string`
  - `zmodem_enabled`, `true_color_enabled`, `sixel_enabled`

### IPC/API
- New `window.api.zmodem` namespace with 6 methods
- Updated `SshConnectPayload` with new SSH options
- Enhanced `ssh:connect` handler with agent forwarding & keepalive

### UI
- ConnectionDialog Advanced tab expanded with:
  - SSH Agent Forwarding toggle
  - Keep-alive settings (interval, count max, timeout)
  - Anti-idle settings (enable, interval, string)
  - Zmodem file transfer toggle
  - Terminal display options (True Color, Sixel)

## ✅ Compatibility
- TypeScript: 0 errors
- Build: Successful for all platforms
- Migration: Automatic ALTER TABLE for existing databases

## 📦 Files Changed
- 13 files modified, 2 new files
- ~1,200 lines added

Author: AnasProgrammer2

.cursorignore

@@ -0,0 +1 @@
+# Add directories or file patterns to ignore during indexing (e.g. foo/ or *.csv)

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "netcopilot",
-  "version": "0.13.1",
+  "version": "0.14.0",
   "description": "NetCopilot – AI-powered SSH/Telnet terminal for network engineers",
   "main": "./out/main/index.js",
   "author": {

package.json

@@ -74,6 +74,17 @@ function initSchema(db: Database.Database): void {
       auto_reconnect  INTEGER NOT NULL DEFAULT 1,
       reconnect_delay INTEGER NOT NULL DEFAULT 10,
       proxy_config    TEXT,
+      agent_forwarding INTEGER DEFAULT 0,
+      keepalive_interval INTEGER DEFAULT 30,
+      keepalive_count_max INTEGER DEFAULT 3,
+      ready_timeout   INTEGER DEFAULT 30,
+      proxy_jump_chain TEXT,
+      anti_idle       INTEGER DEFAULT 0,
+      anti_idle_interval INTEGER DEFAULT 60,
+      anti_idle_string TEXT,
+      zmodem_enabled  INTEGER DEFAULT 0,
+      true_color_enabled INTEGER DEFAULT 0,
+      sixel_enabled   INTEGER DEFAULT 0,
       created_at      INTEGER NOT NULL,
       updated_at      INTEGER NOT NULL,
       last_connected_at INTEGER
@@ -129,6 +140,31 @@ function initSchema(db: Database.Database): void {
     db.exec("ALTER TABLE connections ADD COLUMN proxy_config TEXT")
   }
 
+  // Migration for new SSH Advanced Settings columns
+  const newColumns = [
+    { name: 'agent_forwarding', type: 'INTEGER DEFAULT 0' },
+    { name: 'keepalive_interval', type: 'INTEGER DEFAULT 30' },
+    { name: 'keepalive_count_max', type: 'INTEGER DEFAULT 3' },
+    { name: 'ready_timeout', type: 'INTEGER DEFAULT 30' },
+    { name: 'proxy_jump_chain', type: 'TEXT' },
+    { name: 'anti_idle', type: 'INTEGER DEFAULT 0' },
+    { name: 'anti_idle_interval', type: 'INTEGER DEFAULT 60' },
+    { name: 'anti_idle_string', type: 'TEXT' },
+    { name: 'zmodem_enabled', type: 'INTEGER DEFAULT 0' },
+    { name: 'true_color_enabled', type: 'INTEGER DEFAULT 0' },
+    { name: 'sixel_enabled', type: 'INTEGER DEFAULT 0' },
+  ]
+
+  for (const col of newColumns) {
+    if (!colNames.has(col.name)) {
+      try {
+        db.exec(`ALTER TABLE connections ADD COLUMN ${col.name} ${col.type}`)
+      } catch (e) {
+        console.warn(`[db] Failed to add column ${col.name}:`, e)
+      }
+    }
+  }
+
   const blRow = db
     .prepare("SELECT value FROM settings WHERE key = 'ai.blacklist'")
     .get() as { value: string } | undefined
@@ -282,6 +318,21 @@ export function rowToConnection(row: Row): Connection {
     autoReconnect:    Boolean(row.auto_reconnect),
     reconnectDelay:   row.reconnect_delay as number,
     proxyConfig:      row.proxy_config ? safeJsonParse(row.proxy_config as string, undefined) : undefined,
+    // SSH Advanced Settings
+    agentForwarding:  Boolean(row.agent_forwarding),
+    keepAliveInterval: (row.keepalive_interval as number) ?? 30,
+    keepAliveCountMax: (row.keepalive_count_max as number) ?? 3,
+    readyTimeout:     (row.ready_timeout as number) ?? 30,
+    proxyJumpChain:   row.proxy_jump_chain ? safeJsonParse(row.proxy_jump_chain as string, undefined) : undefined,
+    // Anti-idle
+    antiIdle:         Boolean(row.anti_idle),
+    antiIdleInterval: (row.anti_idle_interval as number) ?? 60,
+    antiIdleString:   (row.anti_idle_string as string) || undefined,
+    // Zmodem
+    zmodemEnabled:    Boolean(row.zmodem_enabled),
+    // Terminal display
+    trueColorEnabled: Boolean(row.true_color_enabled),
+    sixelEnabled:     Boolean(row.sixel_enabled),
     createdAt:        row.created_at as number,
     updatedAt:        row.updated_at as number,
     lastConnectedAt:  (row.last_connected_at as number) || undefined,
@@ -310,6 +361,21 @@ export function connToRow(c: Connection): Row {
     auto_reconnect:   c.autoReconnect   ? 1 : 0,
     reconnect_delay:  c.reconnectDelay  ?? 10,
     proxy_config:     c.proxyConfig     ? JSON.stringify(c.proxyConfig) : null,
+    // SSH Advanced Settings
+    agent_forwarding:    c.agentForwarding ? 1 : 0,
+    keepalive_interval:  c.keepAliveInterval ?? 30,
+    keepalive_count_max: c.keepAliveCountMax ?? 3,
+    ready_timeout:       c.readyTimeout ?? 30,
+    proxy_jump_chain:    c.proxyJumpChain ? JSON.stringify(c.proxyJumpChain) : null,
+    // Anti-idle
+    anti_idle:           c.antiIdle ? 1 : 0,
+    anti_idle_interval:  c.antiIdleInterval ?? 60,
+    anti_idle_string:    c.antiIdleString ?? null,
+    // Zmodem
+    zmodem_enabled:      c.zmodemEnabled ? 1 : 0,
+    // Terminal display
+    true_color_enabled:  c.trueColorEnabled ? 1 : 0,
+    sixel_enabled:       c.sixelEnabled ? 1 : 0,
     created_at:       c.createdAt,
     updated_at:       c.updatedAt,
     last_connected_at: c.lastConnectedAt ?? null,