VSIX v1.2.2 — Error Children, Layer Tabs, Revised Health & Walkthrough (v1.51.0)

Error children — method nodes with declared errorTypes expand to show each error type as an amber $(warning) child node. Click a child to jump to that error class definition (workspace symbol search).

Revised health icon semantics:

Icon	Condition
✅	errorTypes.length > 0
⚠️	Bind/Gatekeeper nodes present AND errorTypes empty
⚪	Terminal/Map/Tap only — no fail-able paths
❌	No diagram or registry missing

Layer diagram tabs — the webview panel toolbar now includes _LayerView, _Stats, _ErrorSurface, and _ErrorPropagation tabs alongside _Diagram and _TypeFlow. Tabs not present in the generated file are hidden.

First-run walkthrough — a VS Code walkthrough guides new users through installing a NuGet package, adding [ResultFlow], and opening their first diagram.

Missing package detection — on activate, the extension scans workspace .csproj files. If no ResultFlow package is found, a notification offers "Install Track A", "Install Track B", and "See Demo" buttons. Single-project workspaces auto-detect the project path; multi-project workspaces show a Quick Pick.

Empty-state tree item — when the sidebar tree has no pipelines after a full scan, an info item is shown with install instructions and a link to the REslava.Result.Flow.Demo.

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