fix(signatures): apply reply signature to replies and forwards

app/(main)/[locale]/page.tsx

@@ -61,6 +61,7 @@ import { Input } from "@/components/ui/input";
 import { FilePreviewModal } from "@/components/files/file-preview-modal";
 import { isFilePreviewable } from "@/lib/file-preview";
 import { appendHtmlSignature, appendPlainTextSignature } from "@/lib/signature-utils";
+import { useSignatureStore } from "@/stores/signature-store";
 import { computeReplyThreadingHeaders } from "@/lib/email-threading";
 import { EML_IMPORT_ACCEPT, expandImportableEmails } from "@/lib/eml-import";
 import { findDraftIdentityId, resolveReplyFrom, type ReplyFromResolution } from "@/lib/reply-identity";
@@ -2615,8 +2616,16 @@ export default function Home() {
 
     // Append signature from the sending identity (fall back to primary
     // when the reply-from lives on the same identity but a different alias).
+    // The signature store's reply signature takes precedence over the legacy
+    // identity signature, matching the composer's send path.
+    const signatureStore = useSignatureStore.getState();
+    const replySigId = signatureStore.getIdentityReplySignatureId(sendingIdentity?.id ?? '');
+    const replySig = replySigId ? signatureStore.getSignatureById(replySigId) : undefined;
+    const signatureSource = replySig
+      ? { htmlSignature: replySig.body, textSignature: replySig.plainText }
+      : sendingIdentity;
     const separator = useSettingsStore.getState().signatureSeparatorEnabled;
-    const finalBody = appendPlainTextSignature(body, sendingIdentity, { separator });
+    const finalBody = appendPlainTextSignature(body, signatureSource, { separator });
 
     // When the identity has an HTML signature, send a matching HTML body so the
     // signature keeps its formatting; appendPlainTextSignature would otherwise
@@ -2627,8 +2636,8 @@ export default function Home() {
       .replace(/</g, '&lt;')
       .replace(/>/g, '&gt;')
       .replace(/\n/g, '<br>');
-    const finalHtmlBody = sendingIdentity?.htmlSignature?.trim()
+    const finalHtmlBody = signatureSource?.htmlSignature?.trim()
-      ? appendHtmlSignature(`<div>${escapedBody}</div>`, sendingIdentity, { separator })
+      ? appendHtmlSignature(`<div>${escapedBody}</div>`, signatureSource, { separator })
       : undefined;
 
     const originalEmailId = selectedEmail.id;

components/email/email-composer.tsx

@@ -653,6 +653,15 @@ export function EmailComposer({
     ? currentIdentity
     : primaryIdentity;
 
+  // The signature store (default/reply/per-identity) takes precedence over the
+  // legacy per-identity html/text signature. `selectedSignature` is resolved in
+  // resolveStoreSignatureId for the current mode (compose → default; reply/
+  // forward → reply), so replies and forwards pick up the reply signature.
+  // Falls back to the legacy identity signature when no store signature is set.
+  const effectiveSignature = selectedSignature
+    ? { htmlSignature: selectedSignature.body, textSignature: selectedSignature.plainText }
+    : signatureIdentity;
+
   // Hold the TipTap editor instance so we can swap the embedded signature
   // when the user switches identity in "above quote" mode without rebuilding
   // the whole body (which would lose user edits to the surrounding draft).
@@ -1883,6 +1892,7 @@ export function EmailComposer({
     // duplicate it.
     const signatureAlreadyInBody =
       shouldEmbedSignatureInNewMail ||
+      (!plainTextMode && !!selectedSignature && mode === 'compose') ||
       ((mode === 'reply' || mode === 'replyAll' || mode === 'forward') &&
         signaturePosition === 'above_quote');
 
@@ -1890,11 +1900,11 @@ export function EmailComposer({
     const buildSignatureHtml = (): string => {
       if (signatureAlreadyInBody) return '';
       const sep = signatureSeparatorEnabled ? `<br><br>-- <br>` : `<br><br>`;
-      if (signatureIdentity?.htmlSignature) {
+      if (effectiveSignature?.htmlSignature) {
-        return `${sep}${sanitizeSignatureHtml(signatureIdentity.htmlSignature)}`;
+        return `${sep}${sanitizeSignatureHtml(effectiveSignature.htmlSignature)}`;
       }
-      if (signatureIdentity?.textSignature) {
+      if (effectiveSignature?.textSignature) {
-        return `${sep}${signatureIdentity.textSignature.replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/\n/g, '<br>')}`;
+        return `${sep}${effectiveSignature.textSignature.replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/\n/g, '<br>')}`;
       }
       return '';
     };
@@ -1907,8 +1917,8 @@ export function EmailComposer({
     // In plain text mode, send text/plain only (no HTML body)
     const signatureOpts = { separator: signatureSeparatorEnabled };
     const finalBody = plainTextMode
-      ? (signatureAlreadyInBody ? body : appendPlainTextSignature(body, signatureIdentity, signatureOpts))
+      ? (signatureAlreadyInBody ? body : appendPlainTextSignature(body, effectiveSignature, signatureOpts))
-      : (signatureAlreadyInBody ? htmlToPlainText(body) : appendPlainTextSignature(htmlToPlainText(body), signatureIdentity, signatureOpts));
+      : (signatureAlreadyInBody ? htmlToPlainText(body) : appendPlainTextSignature(htmlToPlainText(body), effectiveSignature, signatureOpts));
 
     const rewritten = plainTextMode ? null : rewriteInlineImages(body);
     const finalHtmlBody = plainTextMode