Terminal size mismatch between `aspire terminal ps` and dashboard causes cursor/input offset issues

[mitchdenny]

Problem

Terminal dimensions are inconsistent between CLI and dashboard for the same WithTerminal(...) resource.

Observed values:

• aspire terminal ps reports 120x30
• Dashboard terminal shows 80x24

These appear to be out of sync.

Repro

1. Start an AppHost with a resource configured using WithTerminal(...).
2. Run aspire terminal ps and observe reported size.
3. Open the terminal in the dashboard and compare displayed size.

Example environment used:

• ~/Code/scratch/testtesa

Impact

This likely contributes to cursor/mouse hit-testing/calculation issues in the dashboard terminal until a resize occurs.

Behavior detail

Mouse cursor calculation issues persist until a resize event is triggered, for example by:

• taking control / making the terminal primary in the dashboard, or
• another primary attach causing a resize.

Expected

CLI and dashboard should remain synchronized on terminal dimensions so cursor/input mapping is correct without requiring manual resize recovery.

[mitchdenny]

Additional analysis note: this may be a cross Aspire/DCP issue rather than dashboard-only.\n\nPlease include boundary analysis between Aspire terminal orchestration/state and DCP terminal/session sizing propagation when investigating.

[mitchdenny]

Additional repro analysis:\n\n- I updated the repro AppHost to explicitly set terminal size via .\n- Scanning for running AppHosts...
�[38;5;12mℹ️�[0m No running AppHosts found in the current directory. Select from all running AppHosts. now correctly reports 50x50.\n- In the dashboard, the terminal still visually appears around 80x24 (effectively unchanged from before).\n\nThis suggests terminal sizing is drifting in at least two places (CLI-side state vs dashboard render/PTY viewport state), rather than a single bad default.\n\nCombined with earlier observations (size/cursor behavior correcting after resize/primary attach), this still points to missing or delayed initial size synchronization on dashboard attach.

[mitchdenny]

Correction to previous comment (formatting got mangled):

Additional repro analysis:

• I updated the repro AppHost to explicitly set terminal size in WithTerminal options to Columns=50 and Rows=50.
• aspire terminal ps correctly reports 50x50.
• In the dashboard, the terminal still visually appears around 80x24 (effectively unchanged from before).

This suggests terminal sizing is drifting in at least two places (CLI-side state vs dashboard render/PTY viewport state), rather than a single bad default.

Combined with earlier observations (size/cursor behavior correcting after resize/primary attach), this still points to missing or delayed initial size synchronization on dashboard attach.