diff --git a/gitnexus/scripts/cross-platform-shard.ts b/gitnexus/scripts/cross-platform-shard.ts
index 2c52dd86b..0cd9fe8d9 100644
--- a/gitnexus/scripts/cross-platform-shard.ts
+++ b/gitnexus/scripts/cross-platform-shard.ts
@@ -36,9 +36,9 @@
  *
  * Only files heavy enough to matter are listed; everything else is carried by
  * {@link PER_FILE_OVERHEAD_SEC} alone. These are load-balancing hints, NOT
- * assertions — no
- * test asserts a runtime, and drift only makes the split slightly less even, so
- * a stale entry is harmless and refreshing them is optional. Deliberately not
+ * assertions — no test measures elapsed time against this table. Missing or
+ * stale heavy entries can still overload a shard; refresh them from failed
+ * CI logs and replay that profile in the partition tests. Deliberately not
  * auto-generated: a committed table is reviewable and works offline, and the
  * alternative (timing files at CI runtime to decide the split) would make the
  * partition depend on the very machine load it is trying to protect against.
@@ -49,13 +49,15 @@ export const WINDOWS_WEIGHTS_SEC: Readonly<Record<string, number>> = {
   'test/integration/cli-e2e.test.ts': 621,
   'test/integration/worker-pool.test.ts': 222,
   'test/unit/incremental-vector-extension-ordering.test.ts': 87,
-  // ESTIMATE, not a measurement (#2841): this suite drives more full
-  // `runFullAnalysis` cycles than the VECTOR sibling above, so the 8 s
-  // PER_FILE_OVERHEAD floor would badly under-charge it and skew the Windows
-  // split — the failure mode that produced the job timeouts this table exists
-  // to prevent. Scaled from the sibling's measured 87 s by analyze-run count.
-  // Replace with a real figure after the first green Windows matrix run.
-  'test/unit/incremental-index-extension-dml-gate.test.ts': 180,
+  // Measured on Windows in run 34014266125 (#3190, 2026-09-06). These DB
+  // suites landed together on shard 3: the old 180s estimate and missing
+  // entries made a ~27-minute recorded load look like an ~12-minute shard.
+  // Upstream speedups may reduce these figures; retaining conservative weights
+  // keeps the expensive suites distributed without changing the watchdog.
+  'test/unit/incremental-index-extension-dml-gate.test.ts': 414,
+  'test/integration/skills-e2e.test.ts': 444,
+  'test/integration/fts-extension-e2e.test.ts': 146,
+  'test/integration/analyze-wal-checkpoint-failure.test.ts': 86,
   'test/integration/cli-limit-e2e.test.ts': 75,
   'test/unit/hooks.test.ts': 26,
   'test/integration/analyze-heap-oom-e2e.test.ts': 23,
diff --git a/gitnexus/test/unit/cross-platform-shard.test.ts b/gitnexus/test/unit/cross-platform-shard.test.ts
index d5e83552e..30a6ecd1d 100644
--- a/gitnexus/test/unit/cross-platform-shard.test.ts
+++ b/gitnexus/test/unit/cross-platform-shard.test.ts
@@ -29,6 +29,33 @@ const allShards = (files: readonly string[], total: number): readonly (readonly
   Array.from({ length: total }, (_unused, i) => shardFiles(files, i + 1, total));
 
 describe('cross-platform shard partition', () => {
+  it('does not recreate the overloaded Windows shard from the #3190 CI run', () => {
+    // Run 34014266125: these serialized DB suites were missing or undercharged
+    // in the scheduling table. Keep the observed profile independent of the
+    // table so deleting a weight cannot make this regression pass again.
+    const observed: Readonly<Record<string, number>> = {
+      'test/integration/skills-e2e.test.ts': 444,
+      'test/unit/incremental-index-extension-dml-gate.test.ts': 414,
+      'test/integration/fts-extension-e2e.test.ts': 146,
+      'test/integration/analyze-wal-checkpoint-failure.test.ts': 86,
+    };
+    const floor = weightOf('test/unmeasured.test.ts');
+    const loads = allShards(ALL_CROSS_PLATFORM, SHARD_TOTAL).map((files) =>
+      files.reduce((sum, file) => sum + Math.max(weightOf(file), (observed[file] ?? 0) + floor), 0),
+    );
+    // This is a deterministic replay of recorded weights, not a timing test.
+    // The runner's existing watchdog remains 20 minutes.
+    expect(Math.max(...loads)).toBeLessThan(20 * 60);
+    const shards = allShards(ALL_CROSS_PLATFORM, SHARD_TOTAL);
+    const heavyweightLocations = [
+      'test/integration/cli-e2e.test.ts',
+      'test/integration/skills-e2e.test.ts',
+      'test/unit/incremental-index-extension-dml-gate.test.ts',
+    ].map((file) => shards.findIndex((files) => files.includes(file)));
+    expect(heavyweightLocations).not.toContain(-1);
+    expect(new Set(heavyweightLocations).size).toBe(SHARD_TOTAL);
+  });
+
   it('covers every file exactly once, with no overlap between shards', () => {
     const shards = allShards(ALL_CROSS_PLATFORM, SHARD_TOTAL);
     const seen = shards.flatMap((s) => [...s]);
@@ -48,7 +75,7 @@ describe('cross-platform shard partition', () => {
     expect(Math.max(...weights)).toBeLessThanOrEqual(ideal * 1.34);
   });
 
-  it('never puts the two heaviest suites on the same shard', () => {
+  it('keeps the CLI and worker-pool suites on different shards', () => {
     // The exact shape of the outage: cli-e2e and worker-pool are 621 s and
     // 222 s, so together they are most of a shard's budget before anything else
     // is scheduled.