⬆️ 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/counter.md

@@ -0,0 +1,25 @@
+# `obiutils.Counter`: Thread-Safe Atomic Counter
+
+A minimal, thread-safe counter implementation in Go.
+
+## Features
+- **Atomic increment/decrement**: `Inc()` and `Dec()` modify the internal counter atomically using a mutex.
+- **Current value retrieval**: `Value()` safely returns the current count without modifying it.
+- **Initial value support**: Constructor accepts an optional initial integer (defaults to `0`).
+- **Closure-based API**: Encapsulates state and synchronization behind clean, functional methods.
+- **No external dependencies**: Uses only the standard library (`sync`).
+
+## Usage Example
+```go
+counter := obiutils.NewCounter(10) // start at 10
+fmt.Println(counter.Inc())         // → 11
+fmt.Println(counter.Dec())         // → 10
+fmt.Println(counter.Value())       // → 10 (unchanged)
+```
+
+## Thread Safety
+All operations are protected by a `sync.Mutex`, ensuring correctness in concurrent environments.
+
+## Design Notes
+- Immutable interface: methods return updated values, not pointers.
+- No reset method provided—intentionally minimal and focused on core counting semantics.