Unilateral exit: put vtxos on-chain without the server

The trustless backstop behind the Ark card's promise. The vtxo's
genesis chain reconstructs to fully-signed txs (keyspend sigs for
cosigned/arkoor transitions, preimage script-path for hark leaves);
they are zero-fee v3 with P2A anchors, so each hop broadcasts as a
[parent, CPFP child] package via esplora POST /txs/package, one
confirmed hop at a time (TRUC allows a single unconfirmed parent).
After the vtxo tx confirms and the CSV exit delta passes, the claim
spends the delayed_sign leaf with only the user key into the wallet's
own receive address.

Settings gains 'Exit on-chain without the server' with live per-exit
status lines; the claim tx is labeled 'Ark exit' in History. Probing
uses /tx/:txid (definitive 404), never /tx/:txid/status, which answers
confirmed:false for unknown txids.

Also: a fresh visitor opening an ark gift link now adopts the gift's
network automatically instead of being sent to Settings.

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

1 files changed, 21 insertions, 0 deletions

diff --git a/src/ark/manager.js b/src/ark/manager.js
index efcc18a..cfc37a9 100644
--- a/src/ark/manager.js
+++ b/src/ark/manager.js
@@ -41,6 +41,7 @@ import {
   prepareOffboard, validateOffboardTx, signOffboardForfeits, finishOffboard,
   P2TR_DUST,
 } from './offboard.js';
+import { signedExitTxs } from './exit.js';
 import { validateVtxo, VtxoValidationError } from './validate.js';
 
 const EMPTY_STATE = () => ({
@@ -268,6 +269,26 @@ export class ArkManager {
     }
   }
 
+  // ---- unilateral exit ----
+  // Marks the vtxo pending and records the action. The ark FEATURE drives the
+  // steps (it owns the on-chain wallet needed for fee-bump coins and the
+  // claim destination); crash-safety comes from the persisted action like
+  // every other flow. signedExitTxs() up front validates the chain is fully
+  // signed before anything is committed.
+  startExit(vtxoId) {
+    const v = this._vtxo(vtxoId);
+    if (!v || v.state !== 'spendable') throw new Error('vtxo is not spendable');
+    const txs = signedExitTxs(this._decoded(v), this.serverPub);
+    const action = {
+      id: `exit-${Date.now()}-${vtxoId.slice(0, 8)}`, type: 'exit', step: 'chain',
+      vtxoId, amountSat: v.amountSat, txids: txs.map((t) => t.txid),
+    };
+    v.state = 'pending';
+    this.state.actions.push(action);
+    this._save();
+    return action;
+  }
+
   // ---- offboard (collaborative exit: all spendable vtxos -> one on-chain output) ----
   async startOffboard(spk, address) {
     if (this.pendingActions().some((a) => a.type === 'offboard')) {