Replace `FarmhandReducers` stub class with typed `ReducerMethods` interface

[jeremyckahn]

Problem

src/components/Farmhand/FarmhandReducers.tsx is a class that extends Component and contains 50+ stub methods that all throw "Unimplemented". At runtime, matching reducer functions replace these stubs. This pattern adds indirection, uses any[] for all method parameters, and has a TODO comment on line 31 that says: "TODO: Replace this with a TypeScript interface."

The current code:

export class FarmhandReducers extends Component<FarmhandProps, FarmhandState> {
  addCowToInventory(...args: any[]) {
    throw new Error("Unimplemented")
  }
  addPeer(...args: any[]) {
    throw new Error("Unimplemented")
  }
  // ... 50+ more stub methods
}

Implementation Plan

Step 1: Define a ReducerMethods interface

Create an interface in src/components/Farmhand/FarmhandReducers.tsx that matches all 50+ reducer method signatures. Each reducer follows the pattern (state: farmhand.state, ...optionalArgs) => farmhand.state.

export interface ReducerMethods {
  addCowToInventory: (state: farmhand.state) => farmhand.state
  addPeer: (state: farmhand.state) => farmhand.state
  adjustLoan: (state: farmhand.state, amount: number) => farmhand.state
  changeCowAutomaticHugState: (state: farmhand.state, cowId: string, enabled: boolean) => farmhand.state
  // ... all 50+ methods with correct signatures
}

To get the correct signatures, look at the reducer implementations in src/game-logic/reducers/. Each exported reducer function defines the parameter types.

Step 2: Create a bound reducers object

Instead of the class with stubs, create a plain object that maps method names to bound reducer functions:

import * as reducers from "../../game-logic/reducers/index.js"

export const reducerMethods: ReducerMethods = {
  addCowToInventory: reducers.addCowToInventory.bind(null),
  addPeer: reducers.addPeer.bind(null),
  // ... all methods
}

Step 3: Update Farmhand component to use the interface directly

The Farmhand component (in src/components/Farmhand/Farmhand.tsx) uses useFarmhand hook which currently interacts with the FarmhandReducers class. Update the hook to work with the ReducerMethods interface directly.

Step 4: Remove the FarmhandReducers class

Delete the FarmhandReducers class entirely, keeping only the ReducerMethods interface and the bound object.

Step 5: Run type checker

npm run check:types

Acceptance Criteria

• ReducerMethods interface is defined with all 50+ method signatures matching the reducers in src/game-logic/reducers/
• FarmhandReducers class is removed (no more stub methods with any[])
• All reducer methods are bound to the Farmhand instance via a plain object
• Zero any[] parameter lists remain in the reducer binding code
• npm run check:types passes with no errors
• npm test passes