feat: multi-connection parallel support

- connection store: connectedIds array, per-connection health/serverInfo maps
- connect() no longer disconnects existing connections
- New switchTo(id), disconnectById(id), isConnectedById(id) methods
- Per-connection health check timers (Map-based)
- ConnectionCard: switch to connected, connect if not, disconnect if active
- MainArea: per-connection tab state (save/restore on switch)
- Connection switcher dropdown in tab bar showing all open connections
- Clean up tab state when connection disconnects

src/stores/connection.ts

@@ -36,16 +36,23 @@ export interface ConnectionConfig {
 export const useConnectionStore = defineStore('connection', () => {
   const connections = ref<ConnectionConfig[]>([])
   const activeId = ref<string | null>(null)
+  const connectedIds = ref<string[]>([])
   const connecting = ref(false)
   const error = ref<string | null>(null)
-  const serverInfo = ref<string | null>(null)
-  const healthOk = ref(true)
-  let healthTimer: ReturnType<typeof setInterval> | null = null
+  const serverInfoMap = ref<Record<string, string>>({})
+  const healthMap = ref<Record<string, boolean>>({})
+  const healthTimers = new Map<string, ReturnType<typeof setInterval>>()
 
   const activeConnection = computed(() =>
     connections.value.find((c: ConnectionConfig) => c.id === activeId.value) ?? null
   )
-  const isConnected = computed(() => activeId.value !== null)
+  const isConnected = computed(() => activeId.value !== null && connectedIds.value.includes(activeId.value))
+  const serverInfo = computed(() => activeId.value ? serverInfoMap.value[activeId.value] ?? null : null)
+  const healthOk = computed(() => activeId.value ? healthMap.value[activeId.value] ?? false : false)
+
+  function isConnectedById(id: string): boolean {
+    return connectedIds.value.includes(id)
+  }
 
   async function loadConnections() {
     connections.value = await window.electronAPI.storage.getConnections()
@@ -66,7 +73,7 @@ export const useConnectionStore = defineStore('connection', () => {
   }
 
   async function deleteConnection(id: string) {
-    if (activeId.value === id) await disconnect()
+    if (connectedIds.value.includes(id)) await disconnectById(id)
     connections.value = await window.electronAPI.storage.deleteConnection(id)
   }
 
@@ -75,6 +82,11 @@ export const useConnectionStore = defineStore('connection', () => {
   }
 
   async function connect(conn: ConnectionConfig) {
+    // If already connected, just switch
+    if (connectedIds.value.includes(conn.id)) {
+      activeId.value = conn.id
+      return
+    }
     connecting.value = true
     error.value = null
     try {
@@ -107,8 +119,9 @@ export const useConnectionStore = defineStore('connection', () => {
         sshPassphrase: conn.sshPassphrase,
       })
       if (result.success) {
+        connectedIds.value.push(conn.id)
         activeId.value = conn.id
-        serverInfo.value = await window.electronAPI.redis.getInfo(conn.id)
+        serverInfoMap.value[conn.id] = await window.electronAPI.redis.getInfo(conn.id)
         startHealthCheck(conn.id)
       } else {
         error.value = result.error || 'Connection failed'
@@ -120,12 +133,26 @@ export const useConnectionStore = defineStore('connection', () => {
     }
   }
 
+  function switchTo(id: string) {
+    if (connectedIds.value.includes(id)) {
+      activeId.value = id
+    }
+  }
+
+  async function disconnectById(id: string) {
+    stopHealthCheck(id)
+    await window.electronAPI.redis.disconnect(id)
+    connectedIds.value = connectedIds.value.filter(i => i !== id)
+    delete serverInfoMap.value[id]
+    delete healthMap.value[id]
+    if (activeId.value === id) {
+      activeId.value = connectedIds.value[0] ?? null
+    }
+  }
+
   async function disconnect() {
-    stopHealthCheck()
     if (activeId.value) {
-      await window.electronAPI.redis.disconnect(activeId.value)
-      activeId.value = null
-      serverInfo.value = null
+      await disconnectById(activeId.value)
     }
   }
 
@@ -133,7 +160,7 @@ export const useConnectionStore = defineStore('connection', () => {
     if (!activeId.value) return ''
     try {
       const info = await window.electronAPI.redis.getInfo(activeId.value)
-      serverInfo.value = info
+      serverInfoMap.value[activeId.value] = info
       return info
     } catch {
       return ''
@@ -141,26 +168,34 @@ export const useConnectionStore = defineStore('connection', () => {
   }
 
   function startHealthCheck(connId: string) {
-    stopHealthCheck()
-    healthOk.value = true
-    healthTimer = setInterval(async () => {
+    stopHealthCheck(connId)
+    healthMap.value[connId] = true
+    const timer = setInterval(async () => {
       try {
         const ok = await window.electronAPI.redis.isConnected(connId)
-        healthOk.value = ok
+        healthMap.value[connId] = ok
         if (!ok && activeId.value === connId) {
-          // Connection lost
           error.value = 'Connection lost'
         }
       } catch {
-        healthOk.value = false
+        healthMap.value[connId] = false
       }
     }, 5000)
+    healthTimers.set(connId, timer)
   }
 
-  function stopHealthCheck() {
-    if (healthTimer) {
-      clearInterval(healthTimer)
-      healthTimer = null
+  function stopHealthCheck(connId?: string) {
+    if (connId) {
+      const timer = healthTimers.get(connId)
+      if (timer) {
+        clearInterval(timer)
+        healthTimers.delete(connId)
+      }
+    } else {
+      for (const [, timer] of healthTimers) {
+        clearInterval(timer)
+      }
+      healthTimers.clear()
     }
   }
 
@@ -238,9 +273,9 @@ export const useConnectionStore = defineStore('connection', () => {
   }
 
   return {
-    connections, activeId, connecting, error, serverInfo, healthOk,
+    connections, activeId, connectedIds, connecting, error, serverInfo, healthOk,
     activeConnection, isConnected,
     loadConnections, decryptPassword, getInfo, saveConnection, deleteConnection, reorderConnections,
-    connect, disconnect, testConnection, exportConnections, importConnections,
+    connect, disconnect, disconnectById, switchTo, isConnectedById, testConnection, exportConnections, importConnections,
   }
 })