refactor: reduce wrapper boilerplate with macros

[darioAnongba]

Summary

Each BDK type wrapper requires ~50-100 lines of repetitive boilerplate (struct definition, From/Into impls, wasm_bindgen getters/setters). Investigate if procedural or declarative macros can reduce this.

Current Pattern

#[wasm_bindgen]
pub struct WasmType(BdkType);

impl From<BdkType> for WasmType { ... }
impl From<WasmType> for BdkType { ... }

#[wasm_bindgen]
impl WasmType {
    #[wasm_bindgen(getter)]
    pub fn field(&self) -> ... { self.0.field.into() }
    // ... repeat for every field
}

Tasks

• Analyze which parts of the pattern are truly repetitive
• Prototype a declarative macro for simple field-forwarding wrappers
• Evaluate if a proc macro is worth the complexity
• Ensure generated code still produces clean TypeScript bindings
• Refactor existing types to use the macro where beneficial