P1: file parsers, sample sheet, discovery, CLI inspect

Readers for IDAT v3, BPM (locus entries v4-v8), CSV manifest, EGT
(data blocks 5-9) and GTC v3-v5 (plus a layout-preserving GTC writer);
sample-sheet validation (IN-001..IN-014), IDAT discovery and pairing
(IN-020..IN-022), message catalogue and exit codes (CLI-014/016),
JSON Lines logging (CLI-007/008), atomic writes (CLI-011), run manifest,
and `simurg inspect`.

Validation (docs/validation/P1.md): GTC, BPM and EGT readers agree
exactly with Illumina BeadArrayFiles on GSA v4 / GDA v1 files; GTCs
round-trip byte-identically; BPM and CSV manifests are consistent.

Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01814GKVzZVL3FuF3DeiZXhv

src/simurg/genotype/__init__.py

@@ -0,0 +1 @@
+"""SimurgArray genotype package."""