v1.20.1

Changed

• Internal code-health pass: 8 files lifted from Yellow to Green/Optimal on the CodeScene scale. No behavior change for MCP callers; same tool list, same response shapes, same error wording. Release exists so existing users on @latest pick up the cleaner code on their next reinstall. Files: main.go (8.30 → 10.0), miro/appcards.go (8.34 → 10.0), miro/items.go (8.62 → 10.0), miro/bulk.go (8.26 → 9.38), miro/diagrams/mermaid.go (7.91 → 9.38), miro/tags.go (8.47 → 9.38), miro/shape.go (8.82 → 9.38), miro/upload.go (8.33 → 9.09).
• Auth-subcommand CLI error prefixes lowercased (Login failed: → login failed:, Logout failed: → logout failed:) to satisfy Go's staticcheck ST1005 convention. CLI-only; never reaches MCP clients or LLM transcripts.

Decomposition recipes applied

• Brain Update* methods (cc 19–24) → per-section body builders + shared buildUpdatePosition / buildUpdateGeometry / updateParentPayload helpers (preserving the empty-string-nulls-parent semantic).
• Sibling Create* / Update* methods → shared validation, shared body skeletons, type-specific result wrappers preserved at the public-API boundary.
• Inline anonymous JSON structs → named raw* types so parse helpers can be split out (parseItemSummary 81 LoC → minimalItemSummary + addItemFullDetails).
• Per-call regex compilation and per-call map literals promoted to package-level (edgeLabelPattern, tagColorAliases).