fix(tests-sdk): include expiry_offset in deferred-execution signed payload

The Authorize instruction binds expiry_offset to the Secp256r1 signature
hash via signed_payload = instructions_hash || accounts_hash || expiry_offset
(u16 LE). Test code was building signed_payload without the expiryBuf,
causing all 7 deferred tests to fail with InvalidMessageHash (3005). Add
expiryBuf at all 6 sign sites; values match the corresponding
createAuthorizeIx expiryOffset arg (4 × 300, 1 × 9000, 1 × 10).

Verification: 65/65 vitest pass against live validator (was 58/65 before).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: onspeedhp

tests-sdk/tests/08-deferred.test.ts

@@ -116,8 +116,10 @@ describe('Deferred Execution', () => {
       ];
       const accountsHash = computeAccountsHash(tx2AccountMetas, compactIxs);
 
-      // Build signed_payload = instructions_hash || accounts_hash
-      const signedPayload = Buffer.concat([instructionsHash, accountsHash]);
+      // Build signed_payload = instructions_hash || accounts_hash || expiry_offset (u16 LE)
+      const expiryBuf = Buffer.alloc(2);
+      expiryBuf.writeUInt16LE(300);
+      const signedPayload = Buffer.concat([instructionsHash, accountsHash, expiryBuf]);
 
       // Sign with Secp256r1
       const { authPayload, precompileIx } = await signSecp256r1({
@@ -240,7 +242,9 @@ describe('Deferred Execution', () => {
         { pubkey: recipient3, isSigner: false, isWritable: true },
       ];
       const accountsHash = computeAccountsHash(tx2AccountMetas, compactIxs);
-      const signedPayload = Buffer.concat([instructionsHash, accountsHash]);
+      const expiryBuf = Buffer.alloc(2);
+      expiryBuf.writeUInt16LE(300);
+      const signedPayload = Buffer.concat([instructionsHash, accountsHash, expiryBuf]);
 
       // Counter is now 2 (after first test incremented to 1)
       const { authPayload, precompileIx } = await signSecp256r1({
@@ -380,7 +384,9 @@ describe('Deferred Execution', () => {
         { pubkey: recipient, isSigner: false, isWritable: true },
       ];
       const accountsHash = computeAccountsHash(tx2AccountMetas, compactIxs);
-      const signedPayload = Buffer.concat([instructionsHash, accountsHash]);
+      const expiryBuf = Buffer.alloc(2);
+      expiryBuf.writeUInt16LE(300);
+      const signedPayload = Buffer.concat([instructionsHash, accountsHash, expiryBuf]);
 
       const { authPayload, precompileIx } = await signSecp256r1({
         key: ownerKey,
@@ -504,7 +510,9 @@ describe('Deferred Execution', () => {
         { pubkey: recipient, isSigner: false, isWritable: true },
       ];
       const accountsHash = computeAccountsHash(tx2AccountMetas, compactIxs);
-      const signedPayload = Buffer.concat([instructionsHash, accountsHash]);
+      const expiryBuf = Buffer.alloc(2);
+      expiryBuf.writeUInt16LE(300);
+      const signedPayload = Buffer.concat([instructionsHash, accountsHash, expiryBuf]);
 
       const { authPayload, precompileIx } = await signSecp256r1({
         key: ownerKey,
@@ -610,7 +618,9 @@ describe('Deferred Execution', () => {
         { pubkey: recipient, isSigner: false, isWritable: true },
       ];
       const accountsHash = computeAccountsHash(tx2AccountMetas, compactIxs);
-      const signedPayload = Buffer.concat([instructionsHash, accountsHash]);
+      const expiryBuf = Buffer.alloc(2);
+      expiryBuf.writeUInt16LE(9000);
+      const signedPayload = Buffer.concat([instructionsHash, accountsHash, expiryBuf]);
 
       const { authPayload, precompileIx } = await signSecp256r1({
         key: ownerKey,
@@ -710,7 +720,9 @@ describe('Deferred Execution', () => {
         { pubkey: recipient, isSigner: false, isWritable: true },
       ];
       const accountsHash = computeAccountsHash(tx2AccountMetas, compactIxs);
-      const signedPayload = Buffer.concat([instructionsHash, accountsHash]);
+      const expiryBuf = Buffer.alloc(2);
+      expiryBuf.writeUInt16LE(10);
+      const signedPayload = Buffer.concat([instructionsHash, accountsHash, expiryBuf]);
 
       const { authPayload, precompileIx } = await signSecp256r1({
         key: ownerKey,