Add configurable server host

[Blaizzy]

Summary

• add a persisted server host setting beside the existing configurable port
• pass the selected host to the server and use it for clients, copied endpoints, active integration profiles, availability checks, and lifecycle smoke tests
• support hostname, IPv4, and IPv6 URL generation while retaining 127.0.0.1 as the backward-compatible default
• show a live countdown and restart a running server three seconds after the latest host or port edit without retriggering on page navigation
• distinguish an address already in use from an invalid host or port in endpoint warnings
• preserve the replacement process and active endpoint when the previous server’s termination callback arrives late
• add color accents to the Developer panel headers for clearer visual separation
• detect existing Hugging Face CLI login credentials without exposing the token, including custom HF_TOKEN_PATH, HF_HOME, and XDG locations
• show the active Hugging Face credential source with a masked suffix and token length
• organize Hugging Face authentication into status, active credential, and custom override sections with replace and logout controls
• update integration coverage and documentation for dynamic hosts

Why

The server port was configurable, but the bind host and several derived URLs were still hard-coded to 127.0.0.1. This prevented users from binding Nativ to another local interface or wildcard address and caused generated integration endpoints to ignore the intended host.

Impact

Users can configure both host and port from the Developer page. Changing either automatically restarts a running server after a three-second debounce, while an offline server remains offline. Existing settings continue to use the loopback default.

Validation

• xcodebuild -project Nativ.xcodeproj -scheme Nativ -configuration Debug -derivedDataPath build/XcodeDerivedData CODE_SIGNING_ALLOWED=NO -skipPackageUpdates test
• 73 tests passed
• git diff --check

[Lazarus-931]

@Blaizzy do you have a screenshot of the UI change to see?

[Blaizzy]

Here you go @Lazarus-931!

Please don't merge after approval this time, I'll do it after some final changes

[Lazarus-931]

understood, this looks nice @Blaizzy!