[Bug]: Three competing controls are jammed together at the chat/preview boundary

Before submitting

• I searched existing issues and did not find a duplicate.
• I included enough detail to reproduce or investigate the problem.

Area

apps/web

Steps to reproduce

1. Open a thread with enough chat history for the vertical scrollbar to appear.
2. Open Browser in the right-side panel.
3. Switch the browser preview to a fixed/responsive viewport so the preview-content resize grab is visible.
4. Move the pointer along the boundary between the chat and preview.
5. Try to use each of these independently: the chat scrollbar, the side-panel width resize grab, and the preview-content resize grab.

Expected behavior

Each interaction should have a distinct and reliable pointer target. The chat scrollbar should remain usable, and resizing the side panel should be clearly distinguishable from resizing the browser preview content.

Actual behavior

Three separate, full-height interaction targets are packed into essentially the same narrow boundary:

• Chat-window scrollbar
• Side-panel resize grab
• Preview-content resize grab

They are difficult to distinguish and target independently. Attempting to use one can hit an adjacent control instead.

CHAT WINDOW                          SIDE PREVIEW PANEL
                                       PREVIEW CONTENT
                     boundary
                        │
chat content ……… [ S ][ P ][ V ] ……… preview
                   │    │    │
                   │    │    └─ preview-content resize grab
                   │    └────── side-panel resize grab
                   └─────────── chat scrollbar

S, P, and V are three narrow, full-height interaction targets
occupying essentially the same boundary.

Impact

Minor bug or occasional failure

Version or commit

T3 Code Alpha 0.0.33

Environment

Windows desktop app, T3 Code Alpha 0.0.33

Logs or stack traces

Screenshots, recordings, or supporting files

e14c94da3bcbb7374a31aa79b3a3d824.mp4

Workaround

No response

Start in apps/web by reproducing the issue with a chat scrollbar, side-panel resize grab, and responsive browser preview resize grab visible at the same boundary. Trace the three pointer targets and separate their usable areas so each interaction is distinguishable and reliable. Re-test the described steps in the Windows desktop app and confirm all three controls work independently.