feat(web): add file manager views with chunked upload and file picker

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

web/src/views/Files/sha256.worker.ts

@@ -0,0 +1,34 @@
+export {}
+declare const self: {
+  onmessage: ((e: MessageEvent) => void) | null
+  postMessage: (message: unknown) => void
+}
+
+self.onmessage = async (e: MessageEvent) => {
+  const file = e.data.file as File
+  try {
+    // Read entire file into ArrayBuffer (with progress reporting)
+    const CHUNK_READ_SIZE = 16 * 1024 * 1024 // 16MB chunks for progress reporting
+    const buffer = new ArrayBuffer(file.size)
+    const view = new Uint8Array(buffer)
+    let offset = 0
+
+    while (offset < file.size) {
+      const end = Math.min(offset + CHUNK_READ_SIZE, file.size)
+      const slice = file.slice(offset, end)
+      const chunkBuffer = await slice.arrayBuffer()
+      view.set(new Uint8Array(chunkBuffer), offset)
+      offset = end
+      self.postMessage({ progress: offset / file.size })
+    }
+
+    // Compute SHA256 on entire buffer at once
+    const hashBuffer = await crypto.subtle.digest('SHA-256', buffer)
+    const hashArray = Array.from(new Uint8Array(hashBuffer))
+    const sha256 = hashArray.map(b => b.toString(16).padStart(2, '0')).join('')
+
+    self.postMessage({ sha256, progress: 1 })
+  } catch (error) {
+    self.postMessage({ error: error instanceof Error ? error.message : 'SHA256 computation failed' })
+  }
+}