zaps: make the card + modal zap counter always visible (0 sats when none)

Diagnosis (live, verified): the zap-totals pipeline is correct end to end —
a seeded receipt queries and sums to the right sats — but of 310 kind-9735
receipts reachable on the relays, ZERO reference any bitvid video, so every
badge was legitimately hidden. That reads as "broken" and profile zaps to a
Lightning address never attach to a video, so hidden-when-zero left the
feature invisible in practice.

Show the counter always, like the view counter it sits beside: "0 sats"
until a receipt lands, then the summed total. Card binder and modal render
no longer gate on sats>0; the badge is revealed on bind/open and re-hidden
on modal close (no video open). Live-checked: 158/158 cards render the
badge. Tests spec-corrected with integrity notes.

Co-Authored-By: Claude Fable 5 <[email protected]>

js/app/modalCoordinator.js

@@ -81,17 +81,16 @@ export function createModalCoordinator(deps) {
     if (!el || !pointer) {
       return;
     }
+    // Always visible while a video is open (mirrors the view counter); a zero
+    // is a real value, not noise to hide.
     const render = () => {
       const sats = getVideoZapTotalSnapshot(pointer);
+      const value = Number.isFinite(sats) && sats > 0 ? sats : 0;
       const text = el.querySelector("[data-zap-total-text]");
-      if (Number.isFinite(sats) && sats > 0) {
-        if (text) {
-          text.textContent = `${formatViewCount(sats)} sats`;
-        }
-        el.classList.remove("hidden");
-      } else {
-        el.classList.add("hidden");
+      if (text) {
+        text.textContent = `${formatViewCount(value)} sats`;
       }
+      el.classList.remove("hidden");
     };
     requestVideoZapTotal(pointer);
     render();