fix: resolve TypeScript compilation errors across 19 files

- naive_bayes_ext5: fix possibly-undefined array mutations
- neighbors/nca: fix exactOptionalPropertyTypes for nComponents
- neighbors_ext13: remove duplicate nTrees getter and stray void member
- neighbors_ext2/5/7, quad_tree: fix array index access patterns
- nn_ext4/5/7/8/11, nn_utils: fix Float64Array types and index access
- pipeline/index: explicit named re-exports to resolve ambiguity
- random_proj_ext/random_projection_ext: fix function name references
- utils/arrayfuncs: add non-null assertions for index access
- utils/persistence: use bracket notation for index signature properties
- utils/random: fix array swap patterns

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: github-actions[bot]

src/neural_network/nn_utils.ts

@@ -129,11 +129,11 @@ export class BatchNormLayer {
     if (training) {
       const mean = new Float64Array(this.nFeatures);
       for (const row of X)
-        for (let j = 0; j < this.nFeatures; j++) mean[j] += (row[j] ?? 0) / n;
+        for (let j = 0; j < this.nFeatures; j++) mean[j] = (mean[j] ?? 0) + (row[j] ?? 0) / n;
       const variance = new Float64Array(this.nFeatures);
       for (const row of X)
         for (let j = 0; j < this.nFeatures; j++)
-          variance[j] += ((row[j] ?? 0) - (mean[j] ?? 0)) ** 2 / n;
+          variance[j] = (variance[j] ?? 0) + ((row[j] ?? 0) - (mean[j] ?? 0)) ** 2 / n;
       for (let j = 0; j < this.nFeatures; j++) {
         this.runningMean[j] =
           (1 - this.momentum) * (this.runningMean[j] ?? 0) +

src/utils/arrayfuncs.ts

@@ -67,14 +67,14 @@ export function inplaceDenseColumnScale(
 ): void {
   for (let i = 0; i < nRows; i++) {
     for (let j = 0; j < nCols; j++) {
-      X[i * nCols + j]! *= scale[j];
+      X[i * nCols + j]! *= scale[j]!;
     }
   }
 }
 
 /** Computes cumulative sum in-place (modifies arr). */
 export function cumsum(arr: Float64Array): Float64Array {
-  for (let i = 1; i < arr.length; i++) arr[i]! += arr[i - 1];
+  for (let i = 1; i < arr.length; i++) arr[i]! += arr[i - 1]!;
   return arr;
 }
 

src/utils/persistence.ts

@@ -70,9 +70,9 @@ function deserializeValue(v: unknown): unknown {
   }
   if (typeof v === "object") {
     const obj = v as Record<string, unknown>;
-    if (obj.__typedArray === true) {
-      const type = obj.type as string;
-      const data = obj.data as number[];
+    if (obj['__typedArray'] === true) {
+      const type = obj['type'] as string;
+      const data = obj['data'] as number[];
       switch (type) {
         case "Float64Array":
           return new Float64Array(data);