⬆️ 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/obiseq/iupac_nog.md

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+# Semantic Description of `obiseq` Package
+
+The `obiseq` package provides utilities for handling **IUPAC nucleotide ambiguity codes** in biological sequences.
+
+## Core Components
+
+- `_iupac`: A lookup table mapping lowercase ASCII letters (`a`–`z`) to numeric IUPAC nucleotide codes:
+  - `A=1`, `C=2`, `G=4`, `T/U=8` (standard bases)
+  - Ambiguous codes are bitwise OR combinations:  
+    e.g., `R = A|G = 1+4=5`, `Y = C|T = 2+8=10`, etc.
+- Invalid or non-nucleotide characters map to `0`.
+
+## Key Functionality
+
+### `SameIUPACNuc(a, b byte) bool`
+Performs **case-insensitive comparison** of two nucleotide symbols using IUPAC ambiguity rules.
+
+- Converts uppercase letters to lowercase via bitwise OR (`|= 32`).
+- For valid nucleotides, checks if their IUPAC codes have **non-zero bitwise AND**:
+  - Returns `true` only if the symbols share at least one possible base.
+    *Example*: `'R' & 'A' → (5 & 1) = 1 > 0 ⇒ true`  
+    `'Y' & 'G' → (10 & 4) = 0 ⇒ false`
+- For non-IUPAC or invalid characters, falls back to exact equality (`a == b`).
+
+## Use Case
+
+Enables robust comparison of DNA/RNA sequences where ambiguity codes (e.g., `N`, `R`, `W`) are used—critical for alignment, variant calling, or primer design tools.