fix(laboratory): make pairingReceiveSessionProposal canary metric reliably emit

The "AppKit Receive Session Proposal Timing > 7000ms" Grafana alerts (all 4
regions) were firing on No-Data, not on real latency. Their query targets
HappyPath.sign.timing.pairingReceiveSessionProposal, which the canary only
recorded when pairingCreatedTime was set — and that was captured by scraping a
WalletConnect "set core/pairing/pairing" console log that no longer fires. So
the metric was never published (0 datapoints in CloudWatch), while the
unconditional receiveSessionProposal metric stayed healthy (~1.8s).

Capture pairingCreatedTime deterministically when the wallet begins processing
the connection URI instead of depending on SDK console output, and push the
metric unconditionally. The metric name is unchanged, so the existing Grafana
alert starts receiving data with no dashboard change.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: svenvoskamp

apps/laboratory/tests/shared/fixtures/w3m-wallet-fixture.ts

@@ -15,17 +15,13 @@ interface ModalWalletFixture {
 export const testConnectedMW = base.extend<ModalWalletFixture>({
   walletPage: async ({ context, modalPage, timingRecords }, use) => {
     // Setup
-    let pairingCreatedTime: Date | null = null
     let verificationStartedTime: Date | null = null
 
     timeStart('new WalletPage')
     const walletPage = new WalletPage(await context.newPage())
     timeEnd('new WalletPage')
 
     walletPage.page.on('console', msg => {
-      if (msg.text().includes('set') && msg.text().includes('core/pairing/pairing')) {
-        pairingCreatedTime = new Date()
-      }
       if (msg.text().includes('resolving attestation')) {
         verificationStartedTime = new Date()
       }
@@ -51,6 +47,14 @@ export const testConnectedMW = base.extend<ModalWalletFixture>({
     const uri = await modalPage.getConnectUri(timingRecords)
     timeEnd('modalPage.getConnectUri')
 
+    /*
+     * Pairing is created when the wallet begins processing the connection URI.
+     * Captured deterministically here instead of by scraping the SDK's
+     * "core/pairing/pairing" console log, which stopped firing and left the
+     * pairingReceiveSessionProposal metric permanently unpopulated.
+     */
+    const pairingCreatedTime = new Date()
+
     timeStart('walletPage.connectWithUri')
     await walletPage.connectWithUri(uri)
     timeEnd('walletPage.connectWithUri')
@@ -69,12 +73,10 @@ export const testConnectedMW = base.extend<ModalWalletFixture>({
       timeMs: proposalReceived.getTime() - connectionInitiated.getTime()
     })
 
-    if (pairingCreatedTime) {
-      timingRecords.push({
-        item: 'pairingReceiveSessionProposal',
-        timeMs: proposalReceived.getTime() - (pairingCreatedTime as Date).getTime()
-      })
-    }
+    timingRecords.push({
+      item: 'pairingReceiveSessionProposal',
+      timeMs: proposalReceived.getTime() - pairingCreatedTime.getTime()
+    })
 
     const walletValidator = new WalletValidator(walletPage.page)