Capturing self hosting feedback in issues labeled with 2026-themes.

To track progress: Check when PR submitted, close issue when in insiders.

• Top borders are misaligned on dark 2026 experimental #290401
• Terminal tabs look bad in dark 2026 experimental #290403
• Light 2026 experimental shows white brackets on light background #290407
• Light 2026 experimental shows white badge on light background #290408
• Dark 2026 experimental doesn't have a colored bold color in quick pick #290411
• 2026 experimental themes don't differentiate inline titles #290412
• 2026 experimental themes don't color the quick pick separator #290413
• 2026 theme sign in modal is transparent #290520
• 2026 theme to do hover state and overlay corners #290580
• Comments are not highlighted in 2026 light theme #291026
• 2026 themes: chat input buttons are not foreground color #291114
• 2026 themes: selected and highlighted files are the same color #291115
• 2026 themes: split button hover background color #291116
• 2026 themes: Boolean values have no syntax coloring #291118
• 2026 themes: terminal border overlaps completions #291123