feat(web): add tool settings UI for all core image tools

Adds Zustand file store, useToolProcessor hook for upload/process/download
flow, and 7 settings components: resize (with social media presets), crop
(with aspect ratio presets), rotate/flip, convert, compress (quality +
target size modes), strip-metadata, and color adjustments (brightness,
contrast, saturation, channels, effects). Updates tool-page to render the
appropriate settings panel based on toolId.

apps/web/src/stores/file-store.ts

@@ -0,0 +1,45 @@
+import { create } from "zustand";
+
+interface FileState {
+  files: File[];
+  jobId: string | null;
+  processedUrl: string | null;
+  processing: boolean;
+  error: string | null;
+  originalSize: number | null;
+  processedSize: number | null;
+  setFiles: (files: File[]) => void;
+  setJobId: (id: string) => void;
+  setProcessedUrl: (url: string | null) => void;
+  setProcessing: (v: boolean) => void;
+  setError: (e: string | null) => void;
+  setSizes: (original: number, processed: number) => void;
+  reset: () => void;
+}
+
+export const useFileStore = create<FileState>((set) => ({
+  files: [],
+  jobId: null,
+  processedUrl: null,
+  processing: false,
+  error: null,
+  originalSize: null,
+  processedSize: null,
+  setFiles: (files) => set({ files, error: null }),
+  setJobId: (id) => set({ jobId: id }),
+  setProcessedUrl: (url) => set({ processedUrl: url }),
+  setProcessing: (v) => set({ processing: v }),
+  setError: (e) => set({ error: e, processing: false }),
+  setSizes: (original, processed) =>
+    set({ originalSize: original, processedSize: processed }),
+  reset: () =>
+    set({
+      files: [],
+      jobId: null,
+      processedUrl: null,
+      processing: false,
+      error: null,
+      originalSize: null,
+      processedSize: null,
+    }),
+}));