feat(orbit): per-guest suggestion mute + global pending-cap setting

Two anti-spam knobs the host can dial during a live session:

1. Per-guest suggestion mute — Mic / MicOff toggle next to the
   kick/ban buttons in the participants popover. Symmetric (re-enable
   later). State lives in OrbitState.suggestionBlocked: string[]; the
   guest reads it and disables its own Suggest controls so the user
   sees a clear "muted" state instead of silent failures. Host-side
   sweep also drops their outbox entries as a safety net.

2. Max pending approvals cap — number input in the session-settings
   popover, default 0 (= unlimited so existing sessions are unaffected).
   When set, the host sweep stops folding new outbox entries into the
   approval list once the cap is reached. The OrbitQueueHead surfaces
   "X / Y pending" so guests can see when they're getting close.

State changes are additive on the wire — both fields are optional, with
parseOrbitState defaulting them, so older clients keep working.

evaluateOrbitSuggestGate() centralises the guest-side allow/block check
shared between useOrbitSongRowBehavior and the ContextMenu Add-to-Session
items, plus suggestOrbitTrack as a defensive last line.

i18n: en + de + fr + nl + zh + nb + ru + es.

Also fixes an earlier dedupe-key collision: the (user, trackId) cache
keys were missing their separator (NULL byte slipped in during the
previous patch), so two tracks could share a key and one of them
silently overwrite the other. Restored the space separator.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/hooks/useOrbitHost.ts

@@ -87,7 +87,12 @@ export function useOrbitHost(): void {
       let afterSweep = base;
       try {
         const snaps = await sweepGuestOutboxes(base.sid, base.host);
-        afterSweep = applyOutboxSnapshotsToState(base, snaps);
+        // Hand the cap-check the host's local merged/declined sets so it can
+        // tell which `state.queue` items are still actually awaiting approval.
+        afterSweep = applyOutboxSnapshotsToState(base, snaps, Date.now(), {
+          mergedKeys: new Set(store.mergedSuggestionKeys),
+          declinedKeys: new Set(store.declinedSuggestionKeys),
+        });
       } catch { /* best-effort; keep old participants and queue */ }
 
       // 2) Merge newly-suggested items into the host's local play queue so

src/hooks/useOrbitSongRowBehavior.ts

@@ -1,7 +1,12 @@
 import { useCallback, useRef } from 'react';
 import { useTranslation } from 'react-i18next';
 import { useOrbitStore } from '../store/orbitStore';
-import { suggestOrbitTrack, hostEnqueueToOrbit } from '../utils/orbit';
+import {
+  suggestOrbitTrack,
+  hostEnqueueToOrbit,
+  evaluateOrbitSuggestGate,
+  OrbitSuggestBlockedError,
+} from '../utils/orbit';
 import { showToast } from '../utils/toast';
 
 /**
@@ -43,9 +48,26 @@ export function useOrbitSongRowBehavior() {
       clickTimerRef.current = null;
     }
     if (orbitRole === 'guest') {
+      const gate = evaluateOrbitSuggestGate();
+      if (!gate.allowed && gate.reason === 'muted') {
+        showToast(t('orbit.suggestBlockedMuted'), 3500, 'error');
+        return;
+      }
+      if (!gate.allowed && gate.reason === 'cap-reached') {
+        showToast(t('orbit.suggestBlockedCap'), 3500, 'info');
+        return;
+      }
       suggestOrbitTrack(songId)
         .then(() => showToast(t('orbit.ctxSuggestedToast'), 2200, 'info'))
-        .catch(() => showToast(t('orbit.ctxSuggestFailed'), 3000, 'error'));
+        .catch(err => {
+          if (err instanceof OrbitSuggestBlockedError && err.reason === 'muted') {
+            showToast(t('orbit.suggestBlockedMuted'), 3500, 'error');
+          } else if (err instanceof OrbitSuggestBlockedError && err.reason === 'cap-reached') {
+            showToast(t('orbit.suggestBlockedCap'), 3500, 'info');
+          } else {
+            showToast(t('orbit.ctxSuggestFailed'), 3000, 'error');
+          }
+        });
     } else if (orbitRole === 'host') {
       hostEnqueueToOrbit(songId)
         .then(() => showToast(t('orbit.ctxAddedHostToast'), 2200, 'info'))