fix(apps): restore legacy app ordering toggles for client compatibility

[jukor112]

Restore Legacy App Ordering Configuration (Global + Per-Client)

Summary

This PR restores both the global configuration and per-client settings for Legacy App Ordering (legacy_ordering), which were inadvertently hardcoded to true in v1.17.0.

This allows legacy ordering to be selectively disabled for clients that require unmodified application names, such as the Moonlight CLI and MoonDeck.

Problem

When Legacy App Ordering is enabled, the host prepends hidden Unicode zero-width characters (\u200B and \u200C) to application names returned by the /applist endpoint. These invisible characters preserve a stable custom application order for legacy Moonlight GUI clients.

However, command-line clients such as the Moonlight CLI perform literal string matching against the application names returned by /applist. Because the hidden characters are not stripped, application lookup fails.

Example:

Requested: "Steam"
Returned:  "\u200B\u200CSteam"

As a result, the CLI hangs on:

Loading app list...

before eventually reporting that the application was not found.

Since MoonDeck uses the Moonlight CLI internally, this regression also prevents MoonDeck from launching streams.

Solution

This PR restores the ability to enable or disable legacy ordering both globally and on a per-client basis.

C++ Backend

• Restored parsing and persistence of enable_legacy_ordering in src/confighttp.cpp.
• Replaced the hardcoded value in src/nvhttp.cpp:

const bool enable_legacy_ordering =
    config::sunshine.legacy_ordering &&
    named_cert_p->enable_legacy_ordering;

This combines the global configuration with the per-client override.

Web UI

• Restored the "App ordering for legacy clients" toggle under Configuration → Advanced (Advanced.vue).
• Restored the "Enable legacy ordering" checkbox in the Client Management edit dialog (pin.html).
• Reconnected the Vue state handlers for both settings.

Testing

Functional Verification

1. Open Client Management.
2. Disable Enable legacy ordering for the Moonlight CLI client.
3. Run:

moonlight stream <host_ip> <app_name>

Expected Result

• The Moonlight CLI receives application names without hidden zero-width characters.
• Application lookup succeeds immediately.
• Streaming launches successfully.
• MoonDeck functionality is restored.