diff --git a/lib/compute/derivation_engine.dart b/lib/compute/derivation_engine.dart
index c9e5066a..8be2472b 100644
--- a/lib/compute/derivation_engine.dart
+++ b/lib/compute/derivation_engine.dart
@@ -1712,7 +1712,14 @@ import 'substrate.dart';
 // any single-device install or any pairing where those three signals are not
 // actually contended (`group.length < 2` short-circuits to the unchanged row).
 // kAnalyticsPin/kProtocolPin UNCHANGED: edge-only fix.
-const int kAlgoVersion = 96;
+// 96 → 97 (temp_circadian zero-variance guard, analytics main @ 0441ef9):
+// `_nonparam` divided by `varTot/diffN` with no zero-variance guard, so a
+// flat or heavily-quantized skin-temp window reported
+// interdailyStability=0.0 / intradailyVariability=0.0 as measured instead of
+// withheld — a fabricated-metric bug on `circadian_lifestyle`'s stored
+// output. kAnalyticsPin repinned to analytics main's tip (one commit past
+// PR #75's merge SHA).
+const int kAlgoVersion = 97;
 /// The sibling SHAs this version was derived against, asserted against
 /// pubspec.yaml in test/db_serve_version_and_reads_test.dart.
 ///
@@ -1881,7 +1888,14 @@ const int kAlgoVersion = 96;
 // picking one single-device SHA over the other. Verified: `1cf8e61` (this
 // branch's own pin) IS an ancestor of `fe1464d` — the wearfit protocol
 // commit is already folded in, nothing is lost by moving to the tip.
-const String kAnalyticsPin = '01e8b6e02b2370ae42490a678e6a0a4e3569104c';
+//
+// REPIN (main) @ 0441ef9 — analytics main, one commit past #75 above. Fixes
+// temp_circadian.dart's zero-variance division producing fabricated
+// interdailyStability/intradailyVariability=0.0 instead of null on a flat
+// skin-temp window (see pubspec.yaml's comment beside the `ref:` for the
+// verification command). kAlgoVersion bumped 96 -> 97, see the changelog
+// entry above.
+const String kAnalyticsPin = '0441ef9e6fc6d5681c309ce6341911285e829f20';
 // Repinned to analytics main's tip, which carries BOTH PR #72 (hrv_freq
 // Welch gap guard) and PR #73 (overreachingConjunction rhr quantum guard) —
 // the two independent kAlgoVersion bumps above (93 and 94). Verified both
diff --git a/pubspec.lock b/pubspec.lock
index bb696813..d35cae58 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -937,8 +937,8 @@ packages:
     dependency: "direct main"
     description:
       path: "."
-      ref: "01e8b6e02b2370ae42490a678e6a0a4e3569104c"
-      resolved-ref: "01e8b6e02b2370ae42490a678e6a0a4e3569104c"
+      ref: "0441ef9e6fc6d5681c309ce6341911285e829f20"
+      resolved-ref: "0441ef9e6fc6d5681c309ce6341911285e829f20"
       url: "https://github.com/OpenStrap/analytics.git"
     source: git
     version: "1.0.0"
diff --git a/pubspec.yaml b/pubspec.yaml
index a3905a21..3f873c88 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -483,7 +483,18 @@ dependencies:
       # (see derivation_engine.dart's 94 -> 95 changelog entry), so this got
       # a kAlgoVersion bump despite being narrative-only, not a headline-score
       # change.
-      ref: 01e8b6e02b2370ae42490a678e6a0a4e3569104c
+      #
+      # analytics main @ 0441ef9 (MERGED, one hop past #75 above): fixes
+      # temp_circadian.dart's `_nonparam` dividing by varTot/diffN with no
+      # zero-variance guard, so a flat/heavily-quantized skin-temp window
+      # reported interdailyStability=0.0 / intradailyVariability=0.0 as
+      # measured instead of withheld -- a fabricated-metric bug (matches the
+      # zero-variance discipline circadian_np.dart already had). Changes
+      # stored circadian_lifestyle output for any user with a flat temp
+      # window, so kAlgoVersion bumped (96 -> 97). Verified:
+      #   `git show 0441ef9:lib/src/onehz/wellness/temp_circadian.dart |
+      #      grep -n 'varTot == 0\|diffN == 0'`
+      ref: 0441ef9e6fc6d5681c309ce6341911285e829f20
 
   # BLE — flutter_blue_plus is the maintained cross-platform GATT client.
   flutter_blue_plus: ^1.36.8