Add dynamic breadcrumbs to Header via React Context

Replace hardcoded "Coffee Project / Projects" with a BreadcrumbsContext
that each page registers into via useBreadcrumbs(). The Header reads
breadcrumb items dynamically, renders links for items with href, and
makes "Coffee Project" clickable to open the navigation drawer. Also
removes the unused currentScreenName from Redux appState.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/shared/store/appState/index.ts

@@ -1,25 +1,18 @@
-import type { PayloadAction } from "@reduxjs/toolkit"
-
 import { createSlice } from "@reduxjs/toolkit"
 
 import { AppState } from "./types"
 
-const initialState: AppState = {
-	currentScreenName: "",
-}
+const initialState: AppState = {}
 
 const appStateSlice = createSlice({
 	name: "appState",
 	initialState,
 	reducers: {
-		setCurrentScreenName(state, action: PayloadAction<string>) {
-			state.currentScreenName = action.payload
-		},
-		resetAppState(state) {
-			state.currentScreenName = initialState.currentScreenName
+		resetAppState() {
+			return initialState
 		},
 	},
 })
 
-export const { resetAppState, setCurrentScreenName } = appStateSlice.actions
+export const { resetAppState } = appStateSlice.actions
 export const appStateReducer = appStateSlice.reducer