🤖 fix: preserve SSH host when switching runtime modes (#855)

The regression was introduced in 7087ef4 when adding Local/Worktree/SSH
distinction. The onChange handler for runtime selection was changed
from:
```js
mode === LOCAL ? '' : props.sshHost
```
to:
```js
mode === SSH ? props.sshHost : ''
```

This cleared the SSH host when switching away from SSH mode, losing the
user's configured host when switching back.

## Fix

The SSH host is now stored in a separate localStorage key
(`lastSshHost:{projectPath}`) that persists independently of the runtime
mode. This ensures the SSH host is remembered when switching runtime
modes:

- SSH → Local → SSH
- SSH → Worktree → SSH

## Testing

- Existing tests pass
- All static checks pass

_Generated with `mux`_

Author: ammar-agent

src/browser/components/ChatInput/CreationControls.tsx

@@ -41,8 +41,8 @@ export function CreationControls(props: CreationControlsProps) {
           ]}
           onChange={(newMode) => {
             const mode = newMode as RuntimeMode;
-            // Clear SSH host when switching away from SSH
-            props.onRuntimeChange(mode, mode === RUNTIME_MODE.SSH ? props.sshHost : "");
+            // Preserve SSH host across mode switches so it's remembered when returning to SSH
+            props.onRuntimeChange(mode, props.sshHost);
           }}
           disabled={props.disabled}
           aria-label="Runtime mode"

src/browser/hooks/useDraftWorkspaceSettings.ts

@@ -12,6 +12,7 @@ import {
   getModelKey,
   getRuntimeKey,
   getTrunkBranchKey,
+  getLastSshHostKey,
   getProjectScopeId,
 } from "@/common/constants/storage";
 import type { UIMode } from "@/common/types/mode";
@@ -78,8 +79,16 @@ export function useDraftWorkspaceSettings(
     { listener: true }
   );
 
-  // Parse runtime string into mode and host
-  const { mode: runtimeMode, host: sshHost } = parseRuntimeModeAndHost(runtimeString);
+  // Project-scoped SSH host preference (persisted separately from runtime mode)
+  // This allows the SSH host to be remembered when switching between runtime modes
+  const [lastSshHost, setLastSshHost] = usePersistedState<string>(
+    getLastSshHostKey(projectPath),
+    "",
+    { listener: true }
+  );
+
+  // Parse runtime string into mode (host from runtime string is ignored in favor of lastSshHost)
+  const { mode: runtimeMode } = parseRuntimeModeAndHost(runtimeString);
 
   // Initialize trunk branch from backend recommendation or first branch
   useEffect(() => {
@@ -89,15 +98,19 @@ export function useDraftWorkspaceSettings(
     }
   }, [branches, recommendedTrunk, trunkBranch, setTrunkBranch]);
 
-  // Setter for runtime options (updates persisted runtime string)
+  // Setter for runtime options (updates persisted runtime mode and SSH host separately)
   const setRuntimeOptions = (newMode: RuntimeMode, newHost: string) => {
     const newRuntimeString = buildRuntimeString(newMode, newHost);
     setRuntimeString(newRuntimeString);
+    // Always persist the SSH host separately so it's remembered across mode switches
+    if (newHost) {
+      setLastSshHost(newHost);
+    }
   };
 
   // Helper to get runtime string for IPC calls
   const getRuntimeString = (): string | undefined => {
-    return buildRuntimeString(runtimeMode, sshHost);
+    return buildRuntimeString(runtimeMode, lastSshHost);
   };
 
   return {
@@ -106,7 +119,7 @@ export function useDraftWorkspaceSettings(
       thinkingLevel,
       mode,
       runtimeMode,
-      sshHost,
+      sshHost: lastSshHost,
       trunkBranch,
     },
     setRuntimeOptions,

src/common/constants/storage.ts

@@ -126,6 +126,16 @@ export function getTrunkBranchKey(projectPath: string): string {
   return `trunkBranch:${projectPath}`;
 }
 
+/**
+ * Get the localStorage key for last SSH host preference for a project
+ * Stores the last entered SSH host separately from runtime mode
+ * so it persists when switching between runtime modes
+ * Format: "lastSshHost:{projectPath}"
+ */
+export function getLastSshHostKey(projectPath: string): string {
+  return `lastSshHost:${projectPath}`;
+}
+
 /**
  * Get the localStorage key for the preferred compaction model (global)
  * Format: "preferredCompactionModel"