feat(quickemu): enable SPICE display reconnection for running VMs

[flexiondotorg]

Fixes #1370

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

Checklist:

• I have performed a self-review of my code

[cubic-dev-ai]

1 issue found across 1 file

Confidence score: 3/5

• configure_ports in quickemu unconditionally deletes .spice, which can break the auto-reconnect path by removing the port detection source
• Severity is moderate (6/10) with a concrete reconnection failure risk, so there’s some merge risk despite limited scope
• Pay close attention to quickemu - .spice deletion can cause auto-reconnect to fail.

Prompt for AI agents (all issues)

Check if these issues are valid — if so, understand the root cause of each and fix them.


<file name="quickemu">

<violation number="1" location="quickemu:168">
P2: `configure_ports` deletes the `.spice` file unconditionally, but the reconnection logic later depends on that file to detect the running VM’s SPICE port. This causes the auto-reconnect path to fail when you run quickemu against an already-running VM. Only remove the file when starting a new VM (or leave it intact for running VMs).</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[flexiondotorg]

Thanks for the review, but I believe the implementation is correct. Let me explain the execution flow:

Scenario 1: Starting a NEW VM

1. VM_PID is empty (no running process)
2. Code takes the if [ -z "${VM_PID}" ] branch (line 2789)
3. vm_boot is called → configure_ports runs
4. configure_ports deletes any stale .spice file (line 1414) — correct behaviour
5. If SPICE is enabled, a new .spice file is created with the new port (line 1478)

Scenario 2: Reconnecting to an ALREADY RUNNING VM

1. Lines 2734-2742 check the .pid file and validate the process is running via kill -0
2. VM_PID is set to the running process ID
3. Code takes the else branch (line 2800) — vm_boot is never called
4. Since configure_ports is only called from within vm_boot, it never runs for reconnection
5. The .spice file remains intact
6. Lines 2805-2809 read the .spice file and set display="spice"
7. start_viewer launches the SPICE viewer

The key insight: configure_ports is only invoked when booting a new VM. The reconnection path bypasses vm_boot entirely, so the .spice file is preserved and correctly used for reconnection.