Context menu in IO view

[mamarguerat]

Closes #39

Plan

Native Electron context menu on .io-element in device-detail.html (IO mapping tab).

• Copy: name, color, color inversion, icon, +48V, phase
• Paste: apply to the right-clicked connector, or to every selected one
• Incremental paste: paste across a selection and bump the trailing number in the name (Tom 1 → Tom 2, Tom 3, …). Names are clipped to 12 chars (Connector.setName)
• Reset: new Connector() defaults
• Send changes with forward-to-main as saveConnector already does
• Put the clipboard and the increment helper in one small shared module that Context menu in channel view #40 reuses. Add an assert self-check for the increment

🤖 Generated with Claude Code

[mamarguerat]

Implemented, stacked on #70. Right-click a connector for Copy, Paste, Incremental paste and Reset. Incremental paste adds 1 to the trailing number of the copied name on each paste (Tom 1 → Tom 2 → …), keeping the 12-character limit. There's no multi-select in this view, so it doesn't paste across a selection. Outputs never get +48V or phase. Check: node test/worker.test.js.

🤖 Generated with Claude Code