feat: validate trusted mint registry envelopes

src/lnurlcash/trustedMintMerge.ts

@@ -0,0 +1,43 @@
+// Hostile backup merge policy stays separate from live mint transitions:
+// local records win, and imported trust starts unlocked and unconfirmed.
+
+import type {TrustedMint} from './trustedMints'
+import {isJsonObject} from './jsonParsing'
+import {isValidMintPubkey, type MintTransition} from './trustedMintTransitions'
+
+export const mergeMints = (mints: TrustedMint[], incoming: unknown[]): MintTransition<number> => {
+  const knownServers = new Set(mints.map((mint) => mint.server))
+  const merged = [...mints]
+  let added = 0
+  for (const mint of incoming) {
+    if (
+      !isJsonObject(mint) ||
+      typeof mint.server !== 'string' ||
+      typeof mint.mintPubkey !== 'string' ||
+      typeof mint.addedAt !== 'number' ||
+      !isValidMintPubkey(mint.mintPubkey)
+    ) {
+      continue
+    }
+    if (knownServers.has(mint.server)) continue
+    merged.push({
+      server: mint.server,
+      mintPubkey: mint.mintPubkey.toLowerCase(),
+      addedAt: mint.addedAt,
+      locked: false,
+      unconfirmed: true,
+      nodeAlias: typeof mint.nodeAlias === 'string' ? mint.nodeAlias : undefined,
+      nodeColor: typeof mint.nodeColor === 'string' ? mint.nodeColor : undefined,
+      nodeCapacityMsat:
+        typeof mint.nodeCapacityMsat === 'number' ? mint.nodeCapacityMsat : undefined,
+      nodeNumChannels: typeof mint.nodeNumChannels === 'number' ? mint.nodeNumChannels : undefined,
+      nodeNumPeers: typeof mint.nodeNumPeers === 'number' ? mint.nodeNumPeers : undefined,
+      username: typeof mint.username === 'string' ? mint.username : undefined,
+    })
+    knownServers.add(mint.server)
+    added++
+  }
+  return added === 0
+    ? {mints, result: 0, changed: false}
+    : {mints: merged, result: added, changed: true}
+}