chore(performance): lower the initial-bytes baseline to 1,598,232 bytes

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tools/performance/journey-baselines.json

@@ -3,10 +3,10 @@
     "journeys": {
         "launch": {
             "renderer.initialBytes": {
-                "value": 1619993,
+                "value": 1598232,
                 "unit": "bytes",
                 "updatedAt": "2026-09-27",
-                "evidencePr": 1729,
+                "evidencePr": 1734,
                 "measuredWith": "pnpm nx build web && pnpm run perf:initial-bytes"
             }
         }