⬆️ 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/obidefault/batch.md

@@ -0,0 +1,34 @@
+# ObiDefault Package: Batch Configuration Module
+
+This Go module provides centralized configuration for sequence batching in Obitools, supporting both **count-based** and **memory-aware** batch processing.
+
+## Core Features
+
+- `_BatchSize` / `SetBatchSize()`  
+  Defines and configures the *minimum* number of sequences per batch (default: `1`).  
+  Used internally as `minSeqs` in `RebatchBySize`.
+
+- `_BatchSizeMax()` / `SetBatchSizeMax()`  
+  Sets the *maximum* sequences per batch (default: `2000`). Batches are flushed upon reaching this limit, regardless of memory.
+
+- **CLI & Environment Integration**  
+  Batch size is determined by `--batch-size` CLI flag and/or the `OBIBATCHSIZE` environment variable (via parsing logic not shown here but implied by comments).
+
+- `_BatchMem()` / `SetBatchMem(n int)`  
+  Configures the *maximum memory per batch* (default: `128 MB`). A value of `0` disables memory-based batching, falling back to pure count-based logic.
+
+- `_BatchMemStr()`  
+  Stores the *raw CLI string* passed to `--batch-mem` (e.g., `"256M"`, `"1G"`), enabling human-readable input parsing elsewhere.
+
+## Utility Functions
+
+- `BatchSizePtr()`, `BatchMemPtr()`  
+  Expose pointers to internal variables for direct modification or inter-process sharing.
+
+- `BatchSizeMaxPtr()`, `BatchMemStrPtr()`  
+  Provide read/write access to max-size and raw memory string values.
+
+## Design Intent
+
+- Separates **configuration** (defaults, CLI/env parsing) from **processing logic**, enabling modular and testable batch handling.
+- Supports both scalable, large-scale processing (via count limits) and memory-constrained environments (via soft RAM caps).