⬆️ 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/obingslibrary/marker.md

@@ -0,0 +1,40 @@
+# Semantic Description of `obingslibrary` Marker Module
+
+The `Marker` struct defines a molecular biology primer pair (forward/reverse) for PCR-based sample demultiplexing in high-throughput sequencing workflows. It supports flexible configuration of primer binding, tag (barcode) extraction, mismatch tolerance, and indel handling.
+
+## Core Functionalities
+
+- **Primer Pattern Compilation**:  
+  `Compile()` and `Compile2()` initialize forward/reverse primer patterns using the underlying `obiapat.ApatPattern`, including reverse-complement variants (`cforward`, `creverse`). They accept parameters for maximum error tolerance and indel allowance.
+
+- **Sequence Matching & Demultiplexing**:  
+  `Match()` scans a given sequence (`BioSequence`) for primer binding sites. It prioritizes forward-primer detection, then falls back to reverse if needed. For each match:
+  - Extracts primer region and adjacent tag (barcode).
+  - Computes mismatches.
+  - Links to a pre-registered `PCR` object via the tag pair (`TagPair`) key in internal map.
+
+- **Sample Registration & Lookup**:  
+  `GetPCR()` retrieves or registers a new PCR reaction entry indexed by forward/reverse tag pair (case-insensitive). Enables tracking of sample-specific amplification data.
+
+- **Tag Length Validation**:  
+  `CheckTagLength()` ensures all registered tags have uniform length for both directions; otherwise, returns an error.
+
+- **Configurable Parameters**:  
+  Supports tuning of:
+  - Tag lengths (`Forward_tag_length`, `Reverse_tag_length`)
+  - Spacer between tag and primer (`SetTagSpacer()`)
+  - Delimiter for tag-primer boundary (e.g., `a`, `c`, `g`, `t` or none via `'0'`)
+  - Allowed mismatches and indels per primer (`SetAllowedMismatch()`, `SetTagIndels()`)
+  - Matching strategy: `"strict"` (exact), `"hamming"`, or `"indel"`
+
+- **Matching Strategy Enforcement**:  
+  `SetForward/ReverseMatching()` validates and sets matching modes; invalid values raise errors.
+
+## Design Highlights
+
+- Uses `log.Fatalf` for critical configuration failures (e.g., invalid delimiter).
+- Leverages reference-counted sequences (`Recycle()`) for memory efficiency.
+- Prioritizes forward primer match but gracefully handles reverse orientation.
+- Fully supports case-insensitive tag comparison and normalization.
+
+This module serves as the core engine for sample assignment in amplicon-based NGS pipelines, balancing sensitivity (via error/indel tolerance) and specificity (through tag uniqueness).