[wgqqqqq]

Summary

Integrates the OpenBitFun Generative UI path using OpenUI Lang, with streaming rendering in FlowChat and host-provided components and capabilities.

• Adds product contracts, Rust services, desktop APIs, FlowChat streaming and projection, state ownership, and remote capability support.
• Adds OpenUI and OpenBitFun component libraries, HTML/OpenUI rendering, settings previews, and browser fixtures.
• Removes the superseded Canvas runtime and legacy Generative Widget card paths.
• Harmony profile, phone-specific presentation, and Harmony delivery/acceptance flow are intentionally excluded from this PR and remain available on the local wgq/genui-harmony-local branch for follow-up development.

Validation

• pnpm --dir src/web-ui exec tsc --noEmit -p tsconfig.json (passed)
• Focused GenUI and control-bridge Vitest suites (58 passed)
• cargo test --locked -p openbitfun-product-domains --no-default-features --lib generative_ui (14 passed)
• pnpm run capabilities:check (passed)
• node scripts/generate-genui-contract.mjs --check (passed)
• git diff --check (passed)