refactor(wifi): show available networks before saved networks

[ziuus]

• I have disclosed use of any AI generated code in my commit messages.
  • If you are using an LLM, and do not fully understand the changes it is making to the code base, do not create a PR.
  • In our experience, AI generated code often results in overly complex code that lacks enough context for a proper fix or feature inclusion. This results in considerably longer code reviews. Due to this, AI authored or partially authored PRs may be closed without comment.
• I understand these changes in full and will be able to respond to review comments.
• My change is accurately described in the commit message.
• My contribution is tested and working as described.
• I have read the Developer Certificate of Origin and certify my contribution under its conditions.

Summary

• Moves the visible networks section to render before the known networks section in the WiFi settings page.
• Currently available networks now appear at the top (sorted by signal strength).
• Saved/known networks appear below (sorted alphabetically).
• Matches the UX pattern of other distro DE settings apps where "available networks" take priority over "saved networks."
• Preserves the existing search bar behavior (shown when 15+ networks are visible).

Motivation

Users opening the WiFi settings panel need to see nearby networks first — they're the primary action target. A long list of saved networks pushing available networks to the bottom was confusing and required scrolling.

Test plan

• Open WiFi settings with several available networks and saved networks.
• Verify available networks section appears at the top.
• Verify saved networks section appears below.
• Verify search bar still appears when 15+ networks are in range and filters correctly.
• Verify connecting/disconnecting/forgetting still works for both sections.

[jacobgkau]

The PR template that you removed from the description is required. Please add it back and fill it in.

[ziuus]

Re-requesting review: template has been added back to the PR description per the maintainer's request. Let me know if anything else is needed.

[ziuus]

cc @jacobgkau — I've added the required PR template back to the description (all checkboxes checked: AI disclosed, understand changes, commit message accurate, contribution tested, DCO signed). The body still has the original Summary / Motivation / Test plan. Could you take another look when you have a moment? Thanks.

[ziuus]

cc @jacobgkau — friendly bump on the re-review request. The PR template has been restored with all checkboxes ticked (AI disclosed, understand changes, commit message accurate, contribution tested, DCO signed), and the body retains the original Summary / Motivation / Test plan.

Happy to make any further adjustments if there's something else needed. Thanks for taking a look when you have a moment.