⬆️ 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/obiutils/strings.md

@@ -0,0 +1,33 @@
+# `obiutils` Package Overview
+
+The `obiutils` package provides low-level, high-performance utilities for ASCII string and set manipulation in Go.
+
+### Core Components
+
+- **`AsciiSet[256]bool`**: A compact boolean lookup table for ASCII characters (0–127), optimized for membership tests.
+- **Predefined Sets**:
+  - `AsciiSpaceSet`: Whitespace characters (`\t\n\v\f\r `)
+  - `AsciiDigitSet`, `AsciiUpperSet`, `AsciiLowerSet`
+  - Derived sets: `Alpha` (letters), `Alnum` (alphanumeric)
+
+### Key Functions
+
+- **Set Operations**:
+  - `AsciiSetFromString(s string)`: Build a set from characters in a literal.
+  - `.Contains(c byte)` / `.Union()` / `.Intersect()`: Efficient membership and set algebra.
+
+- **String Parsing & Transformation**:
+  - `UnsafeStringFromBytes([]byte) string`: Zero-copy conversion (⚠️ unsafe; use only when memory safety is externally guaranteed).
+  - `FirstWord(s string)`: Extract first non-whitespace token.
+  - `(AsciiSet).FirstWord(...) (string, error)`: Same as above but validates characters against a restriction set.
+  - `TrimLeft(s string)` (via method on *AsciiSet): Remove leading whitespace using space-aware logic.
+  - `LeftSplitInTwo(s string, sep byte)`: Split at first occurrence of a separator.
+  - `RightSplitInTwo(s string, sep byte)`: Split at last occurrence.
+
+### Design Goals
+
+- **Performance**: Avoid allocations where possible (e.g., `unsafe.String`, direct indexing).
+- **Simplicity**: Focused on ASCII-only operations for speed and predictability.
+- **Safety Trade-offs**: `UnsafeStringFromBytes` trades safety for efficiency; other functions are safe and bounds-checked.
+
+Intended use: embedded systems, parsers, or performance-critical text processing where standard library overhead is undesirable.