Long-report render fast path on by default (issue #121, BUG-1335)

Byte-identical to the legacy path on four fictional charts (PyJHora masked),
-19–26% end to end (median 23%). Short of the 25% written on the ticket; the
product owner chose to turn it on anyway. JYOTISH_REPORT_RENDER_FAST=0 restores
the old path.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DbBXoz1Qk3y9buDv1mkmTu

scripts/report_perf_flags.py

@@ -8,12 +8,14 @@ from __future__ import annotations
 
 import os
 
-# Masked Windows A/B on 2026-10-14. Render shortcuts are byte-identical and use
-# less memory, but the end-to-end drop was 20–23%, short of the 35% gate, so
-# the fast path stays off. Cache hits matched the miss bytes and returned in
-# about 0.06s, under the 1.5s gate. A missing or unknown GITHUB_SHA still
-# disables the cache at the call site.
-RENDER_FAST_DEFAULT = False
+# Masked Windows A/B on 2026-10-14: render shortcuts byte-identical, less memory,
+# end-to-end -20–23%, short of the 35% gate then set, so the path stayed off.
+# Linux A/B on 2026-10-28 (four fictional charts, PyJHora masked): byte-identical
+# again, -19–26% (median 23%). The product owner chose to turn it on anyway
+# (issue #121, option A); JYOTISH_REPORT_RENDER_FAST=0 restores the old path.
+# Cache hits matched the miss bytes and returned in about 0.06s, under the 1.5s
+# gate. A missing or unknown GITHUB_SHA still disables the cache at the call site.
+RENDER_FAST_DEFAULT = True
 REFERENCE_CACHE_DEFAULT = True
 
 _ON = {"1", "true", "yes", "on"}