docs: fix copy-paste errors in LaTeX equation labels and SVG file names across stats/base/dists/*

Propagates fix from 692d07b ("docs: fix copy & paste error in LaTeX
equation label and SVG file in `stats/base/dists/kumaraswamy`") to
sibling distribution packages whose `<equation>` labels and SVG
filenames still reference a different distribution name than the
containing package.

- `stats/base/dists/chisquare/quantile`: `eq:chisquared_quantile_function` -> `eq:chisquare_quantile_function`; SVG renamed accordingly
- `stats/base/dists/chi/cdf`: `eq:chi_chi_cdf` -> `eq:chi_cdf` (drop doubled prefix); SVG renamed accordingly
- `stats/base/dists/halfnormal/stdev`: `eq:half_normal_stdev` -> `eq:halfnormal_stdev`

Author: claude

lib/node_modules/@stdlib/stats/base/dists/chi/cdf/README.md

@@ -26,14 +26,14 @@ limitations under the License.
 
 The [cumulative distribution function][cdf] for a [chi][chi-distribution] random variable is
 
-<!-- <equation class="equation" label="eq:chi_chi_cdf" align="center" raw="F(x;\,k) = P\left(k/2,x^{2}/2\right)" alt="Cumulative distribution function for a chi distribution."> -->
+<!-- <equation class="equation" label="eq:chi_cdf" align="center" raw="F(x;\,k) = P\left(k/2,x^{2}/2\right)" alt="Cumulative distribution function for a chi distribution."> -->
 
 ```math
 F(x;\,k) = P\left(k/2,x^{2}/2\right)
 ```
 
-<!-- <div class="equation" align="center" data-raw-text="F(x;\,k) = P\left(k/2,x^{2}/2\right)" data-equation="eq:chi_chi_cdf">
-    <img src="https://cdn.jsdelivr.net/gh/stdlib-js/stdlib@591cf9d5c3a0cd3c1ceec961e5c49d73a68374cb/lib/node_modules/@stdlib/stats/base/dists/chi/cdf/docs/img/equation_chi_chi_cdf.svg" alt="Cumulative distribution function for a chi distribution.">
+<!-- <div class="equation" align="center" data-raw-text="F(x;\,k) = P\left(k/2,x^{2}/2\right)" data-equation="eq:chi_cdf">
+    <img src="https://cdn.jsdelivr.net/gh/stdlib-js/stdlib@591cf9d5c3a0cd3c1ceec961e5c49d73a68374cb/lib/node_modules/@stdlib/stats/base/dists/chi/cdf/docs/img/equation_chi_cdf.svg" alt="Cumulative distribution function for a chi distribution.">
     <br>
 </div> -->
 

…hi/cdf/docs/img/equation_chi_chi_cdf.svg …ts/chi/cdf/docs/img/equation_chi_cdf.svglib/node_modules/@stdlib/stats/base/dists/chi/cdf/docs/img/equation_chi_chi_cdf.svg renamed to lib/node_modules/@stdlib/stats/base/dists/chi/cdf/docs/img/equation_chi_cdf.svg lib/node_modules/@stdlib/stats/base/dists/chi/cdf/docs/img/equation_chi_chi_cdf.svg renamed to lib/node_modules/@stdlib/stats/base/dists/chi/cdf/docs/img/equation_chi_cdf.svg

@@ -26,14 +26,14 @@ limitations under the License.
 
 The [quantile function][quantile-function] for a [chi-squared][chisquare-distribution] random variable is
 
-<!-- <equation class="equation" label="eq:chisquared_quantile_function" align="center" raw="Q(p; k) = 2 \cdot P^{-1}( p, k/2 )" alt="Quantile function for a chi-squared distribution."> -->
+<!-- <equation class="equation" label="eq:chisquare_quantile_function" align="center" raw="Q(p; k) = 2 \cdot P^{-1}( p, k/2 )" alt="Quantile function for a chi-squared distribution."> -->
 
 ```math
 Q(p; k) = 2 \cdot P^{-1}( p, k/2 )
 ```
 
-<!-- <div class="equation" align="center" data-raw-text="Q(p; k) = 2 \cdot P^{-1}( p, k/2 )" data-equation="eq:chisquared_quantile_function">
-    <img src="https://cdn.jsdelivr.net/gh/stdlib-js/stdlib@51534079fef45e990850102147e8945fb023d1d0/lib/node_modules/@stdlib/stats/base/dists/chisquare/quantile/docs/img/equation_chisquared_quantile_function.svg" alt="Quantile function for a chi-squared distribution.">
+<!-- <div class="equation" align="center" data-raw-text="Q(p; k) = 2 \cdot P^{-1}( p, k/2 )" data-equation="eq:chisquare_quantile_function">
+    <img src="https://cdn.jsdelivr.net/gh/stdlib-js/stdlib@51534079fef45e990850102147e8945fb023d1d0/lib/node_modules/@stdlib/stats/base/dists/chisquare/quantile/docs/img/equation_chisquare_quantile_function.svg" alt="Quantile function for a chi-squared distribution.">
     <br>
 </div> -->
 

lib/node_modules/@stdlib/stats/base/dists/chisquare/quantile/README.md

@@ -28,7 +28,7 @@ limitations under the License.
 
 The [standard deviation][standard-deviation] for a [half-normal][half-normal-distribution] random variable is
 
-<!-- <equation class="equation" label="eq:half_normal_stdev" align="center" raw="\sigma \sqrt{1-\frac{2}{\pi}}" alt="Standard deviation for a half-normal distribution."> -->
+<!-- <equation class="equation" label="eq:halfnormal_stdev" align="center" raw="\sigma \sqrt{1-\frac{2}{\pi}}" alt="Standard deviation for a half-normal distribution."> -->
 
 ```math
 \sigma \sqrt{1-\frac{2}{\pi}}