help: add relay, context menu, find/replace, assets, super-buckets docs; fix flaky tests

Updates help screen with all undocumented features. Fixes F1 blocked
by input suppression filter (allow function keys). Stabilizes card-join
tests with poll loop instead of fixed sleep.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

public/plugins/tests/card-join.test.js

@@ -20,16 +20,24 @@ function selectIds(ids, { bulk = false } = {}) {
     for (const id of ids) state.selectedIds.add(String(id));
 }
 
-async function clickJoin(rightClickTargetEl) {
+async function clickJoin(rightClickTargetEl, winnerId) {
     rightClick(rightClickTargetEl);
     await sleep(150);
     const joinBtn = $$('#ctx-items [data-action="join"]')[0];
     if (!joinBtn) return false;
     click(joinBtn);
     // joinSelectedCards does: fetch full bodies → PATCH winner → N × DELETE
-    // losers → _reloadAll. That's 3+ serial API calls and a full board
-    // re-render, so 400ms was sometimes too tight on slower runs.
-    await sleep(800);
+    // losers → _reloadAll. Poll for the winner to have merged body.
+    for (let i = 0; i < 30; i++) {
+        await sleep(100);
+        if (winnerId) {
+            const c = await getCard(winnerId);
+            if (c?.body?.includes('## ')) return true;
+        } else {
+            await sleep(600);
+            return true;
+        }
+    }
     return true;
 }
 
@@ -109,7 +117,7 @@ describe('Card: Join — sequential selection (first wins)', () => {
         if (!firstEl) return;
         selectIds([first.id, second.id, third.id], { bulk: false });
 
-        const ok = await clickJoin(firstEl);
+        const ok = await clickJoin(firstEl, first.id);
         if (!ok) return;
 
         // Winner survives
@@ -132,7 +140,7 @@ describe('Card: Join — sequential selection (first wins)', () => {
         if (!aEl) return;
         selectIds([a.id, b.id, c.id], { bulk: false });
 
-        const ok = await clickJoin(aEl);
+        const ok = await clickJoin(aEl, a.id);
         if (!ok) return;
 
         const survivor = await getCard(a.id);
@@ -159,7 +167,7 @@ describe('Card: Join — sequential selection (first wins)', () => {
         if (!aEl) return;
         selectIds([a.id, b.id], { bulk: false });
 
-        const ok = await clickJoin(aEl);
+        const ok = await clickJoin(aEl, a.id);
         if (!ok) return;
 
         expect(state.selectedIds.size).toBe(0);
@@ -187,7 +195,7 @@ describe('Card: Join — bulk selection (longest title wins)', () => {
         // join code uses longest-title strategy.
         selectIds([short.id, longer.id, medium.id], { bulk: true });
 
-        const ok = await clickJoin(shortEl);
+        const ok = await clickJoin(shortEl, longer.id);
         if (!ok) return;
 
         // The longest-titled card should be the survivor
@@ -220,7 +228,7 @@ describe('Card: Join — undo', () => {
         if (!winnerEl) return;
         selectIds([winner.id, loser.id], { bulk: false });
 
-        const ok = await clickJoin(winnerEl);
+        const ok = await clickJoin(winnerEl, winner.id);
         if (!ok) return;
 
         // Sanity: loser is gone, winner has merged body