Add buffered rendering methods that encode to a buffer first, then
write the response. This allows returning a proper 500 status code
if encoding fails, unlike the streaming variants which must write
the status code before encoding (an inherent HTTP constraint).
New methods:
- JSONBuf(code int, obj any)
- GOBBuf(code int, obj any)
- WANFBuf(code int, obj any)
- HTMLBuf(code int, name string, obj any)
Trade-off: one extra memory allocation per call in exchange for
correct error status codes on encoding failure.
- Implement ShouldBind with support for JSON, Form, WANF, and GOB formats
- Add ShouldBindForm, ShouldBindGOB, and helper functions for form binding
- Use fmt.Appendf instead of fmt.Sprintf for better performance
- Replace interface{} with any for modern Go style
- Use maps.Copy for cleaner header copying
- Update strings.SplitSeq to use range over strings.Seq
- Remove deprecated placeholder comments and add proper implementations
- Fix reflect.Pointer usage for Go 1.22+ compatibility