Textarea parameters lose characters during typing on Create Workspace page #23418

Bug Description

When filling in textarea parameters on the Create Workspace page, users experience dropped characters, input lag, and inconsistent text during typing. The textarea intermittently reverts to an earlier state, causing typed characters to disappear.

Root Cause

The useSyncFormParameters hook overwrites form values with stale WebSocket responses. The sequence:

1. User types abc in a textarea parameter
2. After a 500ms debounce, the value abc is sent to the server via WebSocket
3. User continues typing — form now holds abcde
4. The server responds with abc (echo of what was sent)
5. useSyncFormParameters sees the server value differs from the form value, overwrites the form back to abc
6. The characters de are lost

Since the textarea is a fully controlled React component, the overwritten form value immediately propagates to the DOM, causing the visible snap-back.

Expected Behavior

Characters typed after the WebSocket request should not be lost. The sync hook should detect that a server response is stale (an echo of what was sent, not a server-side transformation) and preserve the user's in-progress input.

Affected Components

• site/src/modules/hooks/useSyncFormParameters.ts — always applies server value when param.value.valid is true
• site/src/pages/CreateWorkspacePage/CreateWorkspacePageView.tsx — calls the sync hook without stale-response awareness
• site/src/modules/workspaces/DynamicParameter/DynamicParameter.tsx — textarea is fully controlled, fires onChange on every keystroke