ui: make Number and Range bindings type-preserving

[linkdata]

Closes #254.

Summary

• preserve signed integers, unsigned integers, uintptr, float32, float64, and named numeric types end to end
• add custom Number codecs and template bindings, with explicit editable-source tag validation and native read-only states
• send settled Number edits on change with managed-event flushing and canonical reconciliation, while Range sends exact live updates and silently rejects unrepresentable browser values
• remove the float64 adapter APIs and InputFloat, and update documentation plus the 32-bit CI coverage

Testing

• JAWS_REQUIRE_NODE=1 go test -race ./...
• JAWS_REQUIRE_NODE=1 go test ./...
• go vet ./...
• staticcheck ./...
• golangci-lint run
• gosec -quiet ./...
• go build ./...
• GOOS=linux GOARCH=386 CGO_ENABLED=0 go test -exec=true ./lib/bind/... ./lib/ui/...