Refresh VS Code panels after create, install, update, and remove

[Railly]

Context

Mutation commands call rich.refreshAll(), which refreshes internal state and then calls _updateHtml(). That method is currently a no-op, while the actual provider renderer is separate.

Evidence:

• vscode/src/extension.ts:9-16 wires mutation callbacks to refreshAll().
• vscode/src/rich-extension.ts:1137-1144 updates state.
• vscode/src/rich-extension.ts:1262 defines the no-op renderer.
• vscode/src/rich-extension.ts:688 contains the working provider refresh path.

Task

Route state replacement through one update path that refreshes every affected registered provider.

Acceptance criteria

• Refresh, create, install, update, and remove immediately update visible panels.
• Hidden panels receive current state when shown again.
• No panel requires a hide/show cycle to reflect mutations.
• Tests cover each mutation callback and visible panel output.