⬆️ 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/obikmer/kdi_merge.md

@@ -0,0 +1,37 @@
+# K-Way Merge for Sorted k-mer Streams
+
+This Go package implements a **k-way merge** over multiple sorted streams of *k*-mer values (`uint64`). It leverages a **min-heap** to efficiently produce the globally sorted sequence while aggregating duplicate counts across input streams.
+
+## Core Components
+
+- **`mergeItem`**: Stores a value and its source reader index for heap operations.
+- **`mergeHeap`** & `heap.Interface`: Implements a min-heap for efficient retrieval of smallest values.
+- **`KWayMerge`**: Main struct managing the heap and input readers.
+
+## Key Functionality
+
+- **Initialization (`NewKWayMerge`)**:
+  - Takes a slice of `*KdiReader`, each expected to yield sorted values.
+  - Preloads the heap with one value from each reader.
+
+- **Streaming Output (`Next`)**:
+  - Returns the next smallest *k*-mer, its frequency across readers (i.e., how many input streams contained it), and a success flag.
+  - Handles duplicates: pops *all* items equal to the current minimum before advancing readers.
+
+- **Cleanup (`Close`)**:
+  - Closes all underlying `KdiReader`s and returns the first encountered error.
+
+## Use Case
+
+Ideal for merging sorted *k*-mer databases (e.g., from multiple files or processes), enabling:
+- Efficient deduplication with multiplicity tracking.
+- Scalable union/intersection operations on large *k*-mer sets.
+
+## Complexity
+
+| Operation | Time       |
+|-----------|------------|
+| `Next()`  | *O(log k)* (heap ops per unique value) |
+| Init      | *O(k)*     |
+
+Where `k` = number of input readers.