Trusted widget ABI v2

ABI v2 is the trusted native extension boundary. Side modules share Click’s WebAssembly address space, so only install reviewed, hash-approved packages.

Package the standalone author SDK:

click/scripts/plugin/package-sdk

The output is click/dist/click-widget-sdk and its tarball. Packages declare content-addressed WASM and settings-schema artifacts plus capability requirements. Click verifies hashes before activation and exposes only asynchronous brokered query, subscribe, and invoke callbacks.

Packaged examples are status_dashboard, task_console, and persistent_tty. ABI v1 binaries are unsupported; source migrations replace the old callback table, rename lifecycle exports to click_widget_*, and replace domain-specific direct callbacks with declared generic capability operations.