Feature map rendering artifacts left behind when clicking or resizing window during DBGENG_TTD debugging session

Version and Platform (required):

• Binary Ninja Version: 6.0.10474-dev Ultimate (c9ea4d90)
• OS: Windows 11 Pro
• OS Version: 10.0.26200 (Build 26200)
• CPU Architecture: x64 (AMD64 Family 25 Model 97, running under QEMU/Proxmox virtualization)
• Local or Remote Debugging: Local (DBGENG_TTD)

Bug Description:
When debugging with the DBGENG_TTD backend, the feature map panel on the right side of the disassembly view renders incorrectly. Two related rendering artifacts occur:

1. Previously rendered lines/marks in the feature map do not disappear or get cleared when clicking within the feature map.
2. Resizing the window leaves visual trails/residue in the feature map area instead of properly redrawing.

Steps To Reproduce:

1. Open a binary (e.g. helloworld.exe) in Binary Ninja
2. Start a local debug session using the DBGENG_TTD
3. Observe the feature map panel on the right side of the disassembly view
4. Click on various positions within the feature map
5. Observe that previous line marks remain rendered instead of clearing
6. Resize the main window
7. Observe leftover rendering trails/artifacts in the feature map area

Expected Behavior:
The feature map should redraw cleanly on click and on window resize, with no leftover visual artifacts or stale line marks from previous states.

Screenshots/Video Recording:

Binary:

Additional Information:
System info (via systeminfo):

• Host: DESKTOP-01C7LS4
• System Manufacturer/Model: QEMU Standard PC (Q35 + ICH9, 2009) — running in a virtualized environment (Proxmox)
• BIOS: Proxmox distribution of EDK II 4.2025.02-4~bpo12+1
• Total Physical Memory: 8,152 MB
• Hyper-V/virtualization-based security: Not enabled; hypervisor detected
• Debugger backend: DBGENG_TTD
• Target: helloworld.exe, windows-x86, stopped at InitialBreakpoint (helloworld + 0x12d5)

Reproduce the issue in the feature map panel of the disassembly view using a local DBGENG_TTD session and helloworld.exe. Start by tracing the panel's redraw behavior after clicks and window resizing, then verify that stale line marks and resize trails are cleared. Done means the feature map redraws cleanly in both cases without visual artifacts.