Unmount wizard board pollers when the dialog closes

[joaoantoniocardoso]

Helps #4434

Summary

• Follow-up to frontend goes vroom #4436: disposeWith: this is now the Vue instance, but closing the wizard does not destroy ScriptLoader / DefaultParamLoader (Vuetify 2 dialog stays booted; stepper content is v-show). The 10s fetchCurrentBoard tasks kept running after Close.
• Mount those loaders with v-if="should_open" so Close actually destroys them and the existing OneMoreTime watcher stops the pollers.

Test plan

• Open the setup wizard, skip it, Close. Confirm GET /ardupilot-manager/v1.0/board stops (no pair every ~10s) while staying on home / another page that does not poll the board.
• Re-open the wizard (Remind me later) and confirm Customize still loads scripts/params.
• Continue through Customize while the dialog is open; Continue still validates via param_loader.

Tested on smoke-catalog (192.168.0.124) with this branch served at localhost:8080. After Close, loaders were gone and /board stayed at 0 hits for 37s (was a pair every 10s before). Re-open + ROV on Customize showed Scripts/Parameter Sets for Navigator64 Sub 4.7.1. validateParams() was false until a set was chosen, then true via $refs.param_loader; Continue was not clicked so firmware was not applied.

[github-actions]

Automated PR Review

0. Summary

• Verdict: LGTM

Adds v-if="should_open" to ScriptLoader and DefaultParamLoader inside core/frontend/src/components/wizard/Wizard.vue (step 3). The wizard uses a persistent v-dialog and stepper v-show, so those loaders stayed mounted after Close and their OneMoreTime({ delay: 10000, disposeWith: this }) fetchCurrentBoard pollers kept firing. Gating on should_open lets Vue destroy them, which trips the disposeWith cleanup path — the intended OneMoreTime idiom per AGENTS.md (Common Pitfalls > Frontend > Forgetting cleanup). The ref="param_loader" used by validateParams() on Continue is still available, since Continue only fires while the dialog is open.

No further comments, nice job 👍

Generated by PR Review Bot. This is advisory, a human reviewer must still approve.