feat(discord): show track title in Discord member list (configurable name template) (#885)

* feat(discord): override activity name in member list with track title (configurable template)

The Discord member list and the collapsed Rich Presence card display the
activity's `name` field next to the music icon. Without an override
Discord falls back to the registered application name ("Psysonic"), so
the line reads "Psysonic" while every track plays instead of the actual
track title that comparable players show.

Add a fourth user-configurable template `discordTemplateName` (Settings ->
Integrations -> Discord Rich Presence). The Rust side passes it through
`Activity::new().name(...)` when the rendered template is non-empty; an
empty template falls back to Discord's default application name. Default
template is "{title}".

Tauri boundary: additive optional `nameTemplate` field on the existing
`discord_update_presence` command. Existing call sites that omit it keep
working -- the Rust handler applies the same "{title}" fallback.

* i18n(settings): discord name template label in all locales

Adds the discordTemplateName label across en, de, fr, es, nl, nb, ro,
zh, ru -- shown next to the new "User list line (name)" template input
under Discord Rich Presence.

* docs(release): CHANGELOG and credits for discord name template (PR #885)

src/locales/nb/settings.ts

@@ -221,6 +221,7 @@ export const settings = {
   discordTemplateDetails: 'Primær linje (details)',
   discordTemplateState: 'Sekundær linje (state)',
   discordTemplateLargeText: 'Album-verktøytips (largeText)',
+  discordTemplateName: 'Brukerliste-linje (name)',
   nowPlayingEnabled: 'Vis i "Nå spiller"',
   nowPlayingEnabledDesc: 'Send sporet som spilles av til tjenerens live-lyttervisning. Deaktiver for å stoppe sending av avspillingsdata.',
   enableBandsintown: 'Bandsintown-turnédatoer',