⬆️ 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/obiformats/empty_file.md

@@ -0,0 +1,22 @@
+## `ReadEmptyFile` Function — Semantic Description
+
+- **Package**: `obiformats`, part of the OBITools4 ecosystem for biological sequence handling.
+- **Purpose**: Creates and returns an *empty*, closed iterator over biosequences (`IBioSequence`).
+- **Signature**:  
+  `func ReadEmptyFile(options ...WithOption) (obiiter.IBioSequence, error)`
+- **Input**: Accepts variadic `WithOption` configuration functions (currently unused in this minimal implementation).
+- **Behavior**:
+  - Instantiates a new `IBioSequence` iterator via `obiiter.MakeIBioSequence()`.
+  - Immediately closes the stream using `.Close()` — indicating no data will be yielded.
+- **Output**:
+  - Returns a *terminal* iterator (no elements), suitable as a safe default or fallback.
+  - Error return is always `nil`, since no I/O occurs and the operation is deterministic.
+
+### Semantic Role & Use Cases
+- **Default/Placeholder**: Useful in conditional logic where a valid (but empty) sequence iterator is required when no input file exists or parsing fails.
+- **Consistency**: Ensures callers always receive a well-formed iterator, avoiding `nil` checks.
+- **Resource Safety**: The closed state prevents accidental iteration or memory leaks.
+
+### Design Notes
+- Reflects a *pure-functional* and *fail-safe* pattern: no side effects, deterministic behavior.
+- Aligns with iterator-based I/O design principles in OBITools4 (lazy, composable streams).