feat: add dashboard-icons as icon fallback source

[dbraendle]

Summary

• Adds walkxcode/dashboard-icons as a primary icon source, matching by --name parameter
• When packaging selfhosted apps (Grafana, Proxmox, TrueNAS, etc.) behind authentication, the existing domain-based icon services (logo.dev, Brandfetch, Clearbit, Google Favicons, favicon.ico) fail because they either can't reach the favicon or return an incorrect icon based on the root domain
• Dashboard-icons is tried first by app name; if no match is found, falls back to the existing domain-based services

Problem

When running e.g. pake https://grafana.mylab.local --name Grafana, the icon services try to resolve the favicon for grafana.mylab.local. Since the app is behind auth, /favicon.ico returns a redirect or error. The services then match the root domain and return an incorrect generic icon.

Solution

Before trying domain-based services, attempt to fetch the icon from cdn.jsdelivr.net/gh/walkxcode/dashboard-icons/png/{name}.png using the --name parameter. This covers 500+ popular selfhosted applications. If the name doesn't match any dashboard icon (404), the existing flow continues unchanged.

Test plan

• Tested with --name Grafana → correct Grafana icon fetched
• Verified Proxmox, TrueNAS slugs resolve (HTTP 200)
• Non-matching names fall through to existing domain-based services
• Verify no regression for public URLs (e.g. pake https://twitter.com --name Twitter)

[tw93]

@dbraendle Thanks for the contribution.

I merged this with a follow-up adjustment on top of your branch.

Reason for the change:

• dashboard-icons is useful for self-hosted apps behind auth, so keeping it as a fallback makes sense.
• Putting it first changes behavior for many public sites as well, because the icon set already contains entries like twitter, github, google, notion, and others.
• That means we could override a valid site-specific favicon with a name-based static icon, which is a broader regression than intended.
• I moved dashboard-icons to the final fallback position, after the existing domain-based services fail.
• I also kept slug matching conservative, only exact name and space-to-hyphen, to reduce false positives.

This keeps the benefit for self-hosted and authenticated installs, without changing the normal path for public websites.