⬆️ version bump to v4.5

- Update obioptions.Version from "Release 4.4.29" to "/v/ Release v5"
- Update version.txt from 4.29 → .30
(automated by Makefile)

autodoc/docmd/pkg/obistats/ttest.md

@@ -0,0 +1,37 @@
+# Statistical Hypothesis Testing Module (`obistats`)
+
+This Go package provides implementations of common **t-tests** for comparing sample means under different assumptions. It supports one- and two-sample tests, paired or unpaired designs.
+
+## Core Types
+
+- **`TTestResult`**: Encapsulates the outcome of a t-test, including:
+  - Sample sizes (`N1`, `N2`)
+  - Test statistic value (`T`)
+  - Degrees of freedom (`DoF`)
+  - Alternative hypothesis type (`AltHypothesis`: `LocationDiffers`, `LocationLess`, or `LocationGreater`)
+  - Computed *p*-value (`P`)
+
+- **`TTestSample` interface**: Requires methods `Weight()`, `Mean()`, and `Variance()` — enabling reuse with summary statistics.
+
+## Supported Tests
+
+1. **`TwoSampleTTest(x1, x2)`**  
+   Standard Student’s *t*-test for two independent samples assuming **equal variances** and normality.
+
+2. **`TwoSampleWelchTTest(x1, x2)`**  
+   Welch’s *t*-test for two independent samples **without equal-variance assumption**, using Satterthwaite approximation for degrees of freedom.
+
+3. **`PairedTTest(x1, x2)`**  
+   Paired *t*-test for dependent samples (e.g., before/after), testing mean of differences against `μ0`.
+
+4. **`OneSampleTTest(x)`**  
+   One-sample *t*-test comparing sample mean to a known population mean `μ0`.
+
+## Error Handling
+
+- Returns errors for invalid inputs: zero sample size (`ErrSampleSize`), zero variance (`ErrZeroVariance`), or mismatched paired sample lengths (`ErrMismatchedSamples`).
+
+## Implementation Notes
+
+- *p*-values are computed using the cumulative distribution function (CDF) of the Student’s *t*-distribution.
+- Designed for statistical rigor and modularity, reusing internal utilities (e.g., `Mean`, `StdDev`) from a shared module.