feat(theseus/bchwallet): send — plan, approval overlay, sign, broadcast

Send tab: recipient (cashaddr or legacy, testnet rejected), amount with
BCH/sat toggle and Max, 1-5 sat/B fee slider, live fee/total preview via
planSend. Sending goes plan -> approval-modal (To/Amount/Fee/Total) ->
ECDSA DER + SIGHASH_ALL|FORKID -> blockchain.transaction.broadcast, then
shows the txid with an explorer link. Confirmed coins are spent before
unconfirmed; dust change folds into the fee. Verified end to end against a
fake Fulcrum: broadcast tx re-parsed, sighash recomputed, signature checks.

bundled-addons/bchwallet/index.js

@@ -93,6 +93,20 @@ async function deriveAndStart() {
   catch (e) { setPhase("error", e?.message || String(e)); c.api.log("wallet build failed:", e?.message); }
 }
 
+const fmtBch = (sats) => (Number(sats) / 1e8).toFixed(8).replace(/(\.\d*?[1-9])0+$|\.0+$/, "$1");
+function planFrom(p) {
+  const c = requireReady();
+  const spec = p || {};
+  const targets = Array.isArray(spec.outputs) && spec.outputs.length
+    ? spec.outputs.map((o) => ({ to: o.to, value: o.amount ?? o.value }))
+    : [{ to: spec.to, value: spec.amount ?? spec.value }];
+  return c.wallet.plan({ targets, feeRate: spec.feeRate, sendMax: !!spec.sendMax });
+}
+function describePlan(plan) {
+  const sent = plan.recipients.reduce((a, r) => a + r.value, 0);
+  return { recipients: plan.recipients, fee: plan.fee, feeRate: plan.feeRate, inputs: plan.inputs.length, change: plan.change, total: sent + plan.fee };
+}
+
 function requireReady() {
   if (!ctx || ctx.phase !== "ready" || !ctx.wallet) throw new Error("wallet is not ready (vault locked?)");
   return ctx;
@@ -120,6 +134,28 @@ function registerPanelMessages(api) {
     if (ctx && ctx.root) buildWallet();
     return snapshot();
   });
+  // Send preview — no side effects, used for the live fee/total summary.
+  api.onMessage("planSend", (p, m) => { fromPanel(m); return describePlan(planFrom(p)); });
+  // Send for real: plan -> approval overlay -> sign -> broadcast.
+  api.onMessage("send", async (p, m) => {
+    fromPanel(m);
+    const c = requireReady();
+    const plan = planFrom(p);
+    const d = describePlan(plan);
+    const pick = await api.approvalModal({
+      title: "Send Bitcoin Cash?",
+      origin: "Theseus wallet panel",
+      rows: [
+        { label: "To", value: d.recipients[0].to, mono: true },
+        { label: "Amount", value: fmtBch(d.recipients[0].value) + " BCH", strong: true },
+        { label: "Fee", value: `${d.fee} sat (${d.feeRate} sat/B)` },
+        { label: "Total", value: fmtBch(d.total) + " BCH" },
+      ],
+      actions: [{ id: "send", label: "Send", primary: true }],
+    });
+    if (pick !== "send") throw new Error("cancelled");
+    return c.wallet.signAndBroadcast(plan);
+  });
   // Recovery info: xpub always; the account xprv only after an explicit
   // confirmation in the approval overlay. Import the xprv into any BIP32
   // wallet (branch 0 receive / 1 change) to move funds without Theseus.

bundled-addons/bchwallet/panel.html

@@ -120,7 +120,32 @@
       </div>
     </section>
     <section id="tab-send" hidden>
-      <div class="empty">Sending arrives in the next step.</div>
+      <div class="field">
+        <div class="lbl">Recipient</div>
+        <input type="text" id="sendTo" spellcheck="false" autocomplete="off" placeholder="bitcoincash:q… or legacy 1…">
+        <div class="hint" id="sendToHint"></div>
+      </div>
+      <div class="field">
+        <div class="lbl">Amount</div>
+        <div class="amt">
+          <input type="text" id="sendAmt" inputmode="decimal" autocomplete="off" placeholder="0.00">
+          <div class="unit"><button id="unitBch" class="on" type="button">BCH</button><button id="unitSat" type="button">sat</button></div>
+          <button class="btn sm" id="sendMax" type="button">Max</button>
+        </div>
+      </div>
+      <div class="field">
+        <div class="lbl">Fee</div>
+        <div class="fee"><input type="range" id="feeRate" min="1" max="5" step="1" value="1"><span class="v" id="feeLbl">1 sat/B</span></div>
+      </div>
+      <div class="card">
+        <div class="summary">
+          <div class="k">Amount</div><div class="v" id="sumAmt">—</div>
+          <div class="k">Network fee</div><div class="v" id="sumFee">—</div>
+          <div class="k">Total</div><div class="v" id="sumTotal">—</div>
+        </div>
+      </div>
+      <div class="actions"><button class="btn primary" id="sendBtn" disabled>Send</button></div>
+      <div class="msg" id="sendMsg" hidden></div>
     </section>
     <section id="tab-history" hidden>
       <div id="txlist"></div>

bundled-addons/bchwallet/panel.js

@@ -111,6 +111,77 @@ function flash(btn, text) {
   setTimeout(() => { btn.textContent = old; }, 1200);
 }
 
+// ---- send ------------------------------------------------------------------
+let unit = "bch";
+let sendMax = false;
+let planTimer = null;
+let lastPlan = null;
+function amountSats() {
+  const raw = $("sendAmt").value.trim().replace(/,/g, "");
+  if (!raw) return 0;
+  if (unit === "sat") return Math.round(Number(raw));
+  const [w, f = ""] = raw.split(".");
+  return Number(w || 0) * 1e8 + Math.round(Number("0." + (f || "0")) * 1e8);
+}
+function setUnit(u) {
+  if (u === unit) return;
+  const s = amountSats();
+  unit = u;
+  $("unitBch").classList.toggle("on", u === "bch"); $("unitSat").classList.toggle("on", u === "sat");
+  $("sendAmt").placeholder = u === "bch" ? "0.00" : "0";
+  if (s) $("sendAmt").value = u === "bch" ? fmtBch(s) : String(s);
+}
+$("unitBch").addEventListener("click", () => setUnit("bch"));
+$("unitSat").addEventListener("click", () => setUnit("sat"));
+$("sendMax").addEventListener("click", () => {
+  sendMax = !sendMax;
+  $("sendMax").classList.toggle("primary", sendMax);
+  $("sendAmt").disabled = sendMax;
+  if (!sendMax) $("sendAmt").value = "";
+  schedulePlan();
+});
+$("feeRate").addEventListener("input", () => { $("feeLbl").textContent = $("feeRate").value + " sat/B"; schedulePlan(); });
+["sendTo", "sendAmt"].forEach((id) => $(id).addEventListener("input", () => { if (id === "sendAmt" && sendMax) return; schedulePlan(); }));
+function schedulePlan() { clearTimeout(planTimer); planTimer = setTimeout(updatePlan, 250); }
+async function updatePlan() {
+  const to = $("sendTo").value.trim();
+  const msg = $("sendMsg"); msg.hidden = true;
+  lastPlan = null; $("sendBtn").disabled = true;
+  $("sumAmt").textContent = $("sumFee").textContent = $("sumTotal").textContent = "—";
+  $("sendToHint").textContent = "";
+  if (!to || (!sendMax && !amountSats())) return;
+  try {
+    const p = await S.invoke("planSend", { to, amount: amountSats(), feeRate: Number($("feeRate").value), sendMax });
+    lastPlan = p;
+    $("sendToHint").textContent = p.recipients[0].to !== to ? "→ " + p.recipients[0].to : "";
+    $("sumAmt").textContent = fmtBch(p.recipients[0].value) + " BCH";
+    $("sumFee").textContent = fmtSats(p.fee) + " sat";
+    $("sumTotal").textContent = fmtBch(p.total) + " BCH";
+    if (sendMax) $("sendAmt").value = unit === "bch" ? fmtBch(p.recipients[0].value) : String(p.recipients[0].value);
+    $("sendBtn").disabled = false;
+  } catch (e) {
+    msg.className = "msg err"; msg.textContent = cleanErr(e); msg.hidden = false;
+  }
+}
+$("sendBtn").addEventListener("click", async () => {
+  if (!lastPlan) return;
+  const msg = $("sendMsg"); msg.hidden = true;
+  $("sendBtn").disabled = true; $("sendBtn").textContent = "Waiting for approval…";
+  try {
+    const r = await S.invoke("send", { to: $("sendTo").value.trim(), amount: amountSats(), feeRate: Number($("feeRate").value), sendMax });
+    msg.className = "msg ok";
+    msg.innerHTML = `Sent. <a class="link" data-tx="${esc(r.txid)}">${esc(r.txid.slice(0, 16))}…</a>`;
+    msg.querySelector("a").addEventListener("click", () => openUrl(state.explorerTx + r.txid));
+    msg.hidden = false;
+    $("sendTo").value = ""; $("sendAmt").value = ""; sendMax = false; $("sendMax").classList.remove("primary"); $("sendAmt").disabled = false;
+    lastPlan = null;
+  } catch (e) {
+    const t = cleanErr(e);
+    if (t !== "cancelled") { msg.className = "msg err"; msg.textContent = t; msg.hidden = false; }
+    $("sendBtn").disabled = !lastPlan;
+  } finally { $("sendBtn").textContent = "Send"; }
+});
+
 // ---- settings --------------------------------------------------------------
 let settingsFilled = false;
 function fillSettings() {