Rebuild as single-file offline BIP84 wallet

Replace the SvelteKit/daisyUI prototype with a vanilla JS + hand-rolled CSS
app that Bun bundles (code + scure/noble crypto + QR + CSS) into one
self-contained dist/index.html runnable offline from file://.

Wallet core (src/wallet.js):
- BIP84 native-segwit HD wallet from BIP39 seed (+optional passphrase)
- gap-limit scan of receive/change chains, aggregate balance, tx history
- fresh receive/change addresses; signs with witnessUtxo only (enables
  offline signing with no prev-tx fetch)
- coin selection + fee estimation via btc-signer selectUTXO; send-max;
  manual coin control
- offline JSON snapshot export/import (keyless) + signed-tx hex/QR export
- realtime mempool.space WebSocket: track-addresses -> debounced auto
  refresh of balances/history (no polling); live status badge

UI (src/app.js): clean light paper-wallet; create (with optional, skippable
backup verification) / import flow; receive (QR) / send / history / coins /
tools tabs; clickable logo returns home.

API (src/api.js): mempool.space wrapper with retry/backoff for scan-burst
rate limiting; single network choke-point for offline enforcement.

Verified: BIP84 spec vectors, build/sign/parse for auto/max/manual flows,
snapshot roundtrip, live scan + WebSocket, headless-Chrome UI smoke tests.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

3 files changed, 0 insertions, 363 deletions

diff --git a/src/routes/+layout.svelte b/src/routes/+layout.svelte
deleted file mode 100644
index fe115b3..0000000
--- a/src/routes/+layout.svelte
+++ /dev/null
@@ -1,19 +0,0 @@
-<script lang="ts">
-	import '../app.css';
-
-	let { children } = $props();
-</script>
-
-<div
-	class="container mx-auto max-w-3xl space-y-5 rounded-2xl bg-gray-100 p-8 text-xl shadow-lg"
-	data-theme="light"
->
-	<div class="flex items-center justify-center gap-2">
-		<img src="/bitcoin.svg" />
-		<div>
-			<a href="/" class="mx-auto text-2xl">Adamant</a>
-		</div>
-	</div>
-
-	{@render children()}
-</div>
diff --git a/src/routes/+layout.ts b/src/routes/+layout.ts
deleted file mode 100644
index 89da957..0000000
--- a/src/routes/+layout.ts
+++ /dev/null
@@ -1,2 +0,0 @@
-export const ssr = false;
-export const prerender = true;
diff --git a/src/routes/+page.svelte b/src/routes/+page.svelte
deleted file mode 100644
index 4694a63..0000000
--- a/src/routes/+page.svelte
+++ /dev/null
@@ -1,342 +0,0 @@
-<script>
-	import { hex } from '@scure/base';
-	import { HDKey } from '@scure/bip32';
-	import * as btc from '@scure/btc-signer';
-	import { goto } from '$app/navigation';
-	import { onMount, tick } from 'svelte';
-	import { focus } from '$lib';
-	import { generateMnemonic, mnemonicToSeedSync } from '@scure/bip39';
-	import { wordlist } from '@scure/bip39/wordlists/english';
-	import Copy from '$lib/Copy.svelte';
-
-	import 'iconify-icon';
-
-	import { getAddress, p2wpkh } from '@scure/btc-signer/payment';
-
-	const pastePassword = async () => {
-		password = await navigator.clipboard.readText();
-	};
-
-	const pasteSeed = async () => {
-		mnemonic = await navigator.clipboard.readText();
-	};
-
-	const togglePassword = () => (revealPassword = !revealPassword);
-	const toggleSeed = () => (revealSeed = !revealSeed);
-
-	let NET = 'bitcoin';
-	const versions = {
-		bitcoin: {
-			private: 0x0488ade4,
-			public: 0x0488b21e
-		},
-		regtest: {
-			private: 0x04358394,
-			public: 0x043587cf
-		}
-	}[NET];
-
-	const network = {
-		bitcoin: {
-			bech32: 'bc',
-			pubKeyHash: 0x00,
-			scriptHash: 0x05,
-			wif: 0x80
-		},
-		regtest: {
-			bech32: 'bcrt',
-			pubKeyHash: 0x6f,
-			scriptHash: 0xc4,
-			wif: 0xef
-		}
-	}[NET];
-
-	let fees, rate;
-	let utxos = [];
-
-	let api = 'https://mempool.space/api';
-	let amt = $state();
-	// let destination = $state('bc1qqz6nlwxwmfqw0v864p5sggqst2xf0mevtyc579');
-	// let password = $state('123');
-	// let mnemonic = $state(
-	// 	'lizard armor follow dinner quarter talent truly among column rebuild arrest mix'
-	// );
-	// let withdrawing = $state(true);
-	let destination = $state();
-	let password = $state('');
-	let mnemonic = $state('');
-	let withdrawing = $state();
-	let revealPassword = $state(false);
-	let revealSeed = $state(true);
-
-	let balance = $state();
-	let pending = $state();
-
-	let loading = $state();
-
-	let generate = async () => {
-		mnemonic = await generateMnemonic(wordlist);
-	};
-
-	onMount(async () => {
-		// setTimeout(checkBalance, 1000);
-
-		if (NET === 'regtest') {
-			fees = { fastestFee: 281, halfHourFee: 271, hourFee: 256, economyFee: 44, minimumFee: 22 };
-		} else {
-			fees = await fetch(`${api}/v1/fees/recommended`).then((r) => r.json());
-		}
-
-		rate = fees['halfHourFee'];
-	});
-
-	let getHex = async (txid) => {
-		if (txid instanceof Uint8Array) txid = hex.encode(txid);
-		return hex.decode(await fetch(`${api}/tx/${txid}/hex`).then((r) => r.text()));
-	};
-
-	let node = $derived.by(() => {
-		if (!mnemonic) return;
-		try {
-			const seed = mnemonicToSeedSync(mnemonic.trim(), password.trim());
-			const root = HDKey.fromMasterSeed(seed, versions);
-			return root.derive(`m/84'/0'/0'/0/0`);
-		} catch (e) {}
-	});
-
-	let address = $derived(node ? p2wpkh(node.publicKey).address : undefined);
-	let txid = $state();
-
-	let checkBalance = async (e) => {
-		e?.preventDefault();
-		loading = true;
-		utxos = await fetch(`${api}/address/${address}/utxo`).then((r) => r.json());
-
-		balance = 0;
-		pending = 0;
-
-		for (let { value, status } of utxos) {
-			if (status.confirmed) balance += value;
-			else pending += value;
-		}
-
-		loading = false;
-	};
-
-	let send = async () => {
-		let sats = 100000000;
-		let b = (n) => (Number(n) / sats).toFixed(8);
-		let inputs = [];
-		let outputs = [];
-		let fee, tx;
-
-		let i = 0;
-		let total = 0n;
-		let amount = BigInt(amt);
-
-		while (total < amount) {
-			total += BigInt(utxos[i].value);
-			i++;
-			if (i > utxos.length) throw new Error('insufficient funds');
-		}
-
-		let change = total - amount;
-
-		tx = new btc.Transaction();
-
-		for await (let { input, vout, txid } of utxos.slice(0, i)) {
-			tx.addInput({
-				txid,
-				index: vout,
-				nonWitnessUtxo: await getHex(txid),
-				sequence: 0xfffffffd
-			});
-		}
-
-		tx.addOutputAddress(destination, amount, network);
-		tx.addOutputAddress(address, change, network);
-
-		console.log(tx.unsignedTx.length);
-
-		while (i <= utxos.length) {
-			fee = BigInt(rate) * BigInt(tx.unsignedTx.length * 2);
-
-			if (fee <= change) {
-				let q = new btc.Transaction();
-				for (let i = 0; i < tx.inputsLength; i++) {
-					let input = tx.getInput(i);
-
-					let nonWitnessUtxo = await getHex(input.txid);
-					q.addInput({ ...input, nonWitnessUtxo });
-				}
-				q.addOutput(tx.getOutput(0));
-				q.addOutputAddress(address, change - fee, network);
-				tx = q;
-
-				break;
-			} else {
-				if (i === utxos.length) {
-					if (fee > amount) throw new Error('insufficient funds');
-					else {
-						let q = new btc.Transaction();
-						for (let i = 0; i < tx.inputsLength; i++) {
-							let input = tx.getInput(i);
-
-							let nonWitnessUtxo = await getHex(input.txid);
-							q.addInput({ ...input, nonWitnessUtxo });
-						}
-
-						q.addOutputAddress(destination, total - fee, network);
-
-						tx = q;
-						break;
-					}
-				}
-
-				let { txid, vout } = utxos[++i];
-				tx.addInput({
-					hash: txid,
-					index: vout,
-					nonWitnessUtxo: await getHex(txid)
-				});
-			}
-		}
-
-		let privkey = node.privateKey;
-		for (let i = 0; i < tx.inputsLength; i++) {
-			tx.signIdx(privkey, 0);
-			let input = tx.getInput(i);
-			let utxo = input.nonWitnessUtxo.outputs[input.index];
-
-			inputs = [
-				...inputs,
-				{
-					address: btc.Address(network).encode(btc.OutScript.decode(utxo.script)),
-					amount: b(utxo.amount)
-				}
-			];
-		}
-
-		outputs = tx.outputs.map((o) => ({
-			address: btc.Address(network).encode(btc.OutScript.decode(o.script)),
-			amount: b(o.amount)
-		}));
-
-		tx.finalize();
-
-		txid = await fetch(`${api}/tx`, {
-			method: 'POST',
-			body: tx.hex
-		}).then((r) => r.text());
-	};
-</script>
-
-<form class="space-y-5" onsubmit={checkBalance}>
-	<div class="flex flex-wrap gap-2">
-		{#if revealSeed}
-			<textarea
-				use:focus
-				class="textarea w-full min-w-[200px] sm:w-auto"
-				placeholder="Seed phrase"
-				bind:value={mnemonic}
-			></textarea>
-		{:else}
-			<input
-				type="password"
-				class="input w-full min-w-[200px] grow sm:w-auto"
-				placeholder="Seed phrase"
-				bind:value={mnemonic}
-			/>
-		{/if}
-		<div class="flex flex-wrap w-full justify-center sm:w-auto">
-			<button type="button" class="btn !w-auto grow" onclick={toggleSeed}>
-				<iconify-icon icon={revealSeed ? 'ph:eye-bold' : 'ph:eye-slash-bold'} width={32} />
-			</button>
-			<Copy bind:text={mnemonic} />
-			<button type="button" class="btn !w-auto grow" onclick={pasteSeed}>
-				<iconify-icon icon="ph:clipboard-text-bold" width={32} />
-			</button>
-			<button type="button" class="btn !w-auto grow" onclick={generate}>
-				<iconify-icon icon="ph:dice-five-bold" width={32} />
-			</button>
-		</div>
-	</div>
-
-	<div class="flex flex-wrap gap-2">
-		{#if revealPassword}
-			<input
-				class="input w-full min-w-[200px] sm:w-auto"
-				placeholder="Passphrase"
-				bind:value={password}
-			/>
-		{:else}
-			<input
-				type="password"
-				class="input w-full min-w-[200px] sm:w-auto"
-				placeholder="Passphrase"
-				bind:value={password}
-			/>
-		{/if}
-
-		<div class="flex w-full justify-center sm:w-auto">
-			<button type="button" class="btn !w-auto grow" onclick={togglePassword}>
-				<iconify-icon icon={revealPassword ? 'ph:eye-bold' : 'ph:eye-slash-bold'} width={32} />
-			</button>
-
-			<Copy bind:text={password} />
-
-			<button type="button" class="btn !w-auto grow" onclick={pastePassword}>
-				<iconify-icon icon="ph:clipboard-text-bold" width={32} />
-			</button>
-		</div>
-	</div>
-
-	<div>
-		{#if address}
-			<div class="flex flex-wrap items-center gap-2 break-all text-base">
-				<div>
-					{address}
-				</div>
-
-				<div class="flex w-full justify-center sm:w-auto">
-					<Copy bind:text={address} />
-					<button type="submit" class="btn !w-auto grow ml-auto">
-						<iconify-icon icon="ph:coins-bold" width={32} />
-					</button>
-				</div>
-			</div>
-		{/if}
-	</div>
-</form>
-
-{#if loading}
-	<div>
-		<div class="loading loading-spinner"></div>
-	</div>
-{:else if typeof balance !== 'undefined'}
-	<div class="flex items-center gap-2">
-		<div>
-			Balance: {balance + pending} sats
-		</div>
-		{#if balance + pending > 0}
-			<button type="submit" class="btn ml-auto" onclick={() => (withdrawing = true)}>
-				Withdraw</button
-			>
-		{/if}
-	</div>
-{/if}
-
-{#if txid}
-	<div class="flex">
-		<div>Transaction completed!</div>
-		<div class="ml-auto">
-			<a href={`https://mempool.space/tx/${txid}`} class="btn">Details</a>
-		</div>
-	</div>
-{:else if withdrawing}
-	<input class="input w-full" placeholder="Destination address" bind:value={destination} />
-
-	<input class="input w-full" placeholder="Amount" bind:value={amt} />
-
-	<button type="submit" class="btn ml-auto" onclick={send}> Send</button>
-{/if}