refactor(page): parse the file list with its schema instead of a sanitizer

The desktop wrapper already types and redacts the search result; the page
strips unknown fields with the contract schema like readDir does, and the
last shell-era sanitizer module goes.

Claude-Session: https://claude.ai/code/session_01JNnE9qzUZMMnqpZWCqM3nb

src/mobile-web/src/mobile-web-file-host-reads.test.ts

@@ -165,7 +165,7 @@ describe('page-safe file listing and text', () => {
       }
     })
     respond({
-      files: [{ relativePath: 'docs/report.md', kind: 'text' }],
+      files: [{ relativePath: 'docs/report.md', basename: 'report.md', kind: 'text' }],
       totalCount: 1,
       truncated: false,
       futureField: true

src/mobile-web/src/mobile-web-file-request-client.ts

@@ -1,9 +1,9 @@
 import { z } from 'zod'
-import { sanitizeListResult } from '../../shared/mobile-web/file-list-presentation'
 import { projectMobileWebHostFileContent } from './mobile-web-host-file-content'
 import {
   MOBILE_WEB_FILE_CHUNK_MAX_BYTES,
   MobileWebFileListPayloadSchema,
+  MobileWebFileListResultSchema,
   MobileWebFileOpenPayloadSchema,
   MobileWebFileReadPayloadSchema,
   MobileWebFileSearchPayloadSchema,
@@ -47,6 +47,19 @@ const WriteResultSchema = z.union([
   z.object({ outcome: z.enum(['conflict', 'too_large']) })
 ])
 
+// The desktop already types and redacts the list; the page only strips fields it does not know.
+function projectListResult(
+  result: unknown,
+  workspaceId: string,
+  limit: number
+): MobileWebFileListResult {
+  const parsed = MobileWebFileListResultSchema.omit({ workspaceId: true }).strip().safeParse(result)
+  if (!parsed.success || parsed.data.files.length > limit) {
+    throw new MobileWebBridgeClientError('invalid_message', false)
+  }
+  return { ...parsed.data, workspaceId }
+}
+
 export class MobileWebFileRequestClient extends MobileWebFileReadClient {
   list(
     payload: MobileWebFileListPayload,
@@ -59,7 +72,7 @@ export class MobileWebFileRequestClient extends MobileWebFileReadClient {
       'mobileWeb.files.searchPaths',
       payload.workspaceId,
       { query: '', limit: payload.limit },
-      (result) => sanitizeListResult(result, payload.workspaceId, undefined, payload.limit),
+      (result) => projectListResult(result, payload.workspaceId, payload.limit),
       options
     )
   }
@@ -75,7 +88,7 @@ export class MobileWebFileRequestClient extends MobileWebFileReadClient {
       'mobileWeb.files.searchPaths',
       payload.workspaceId,
       { query: payload.query, limit: payload.limit },
-      (result) => sanitizeListResult(result, payload.workspaceId, undefined, payload.limit),
+      (result) => projectListResult(result, payload.workspaceId, payload.limit),
       options
     )
   }

src/shared/mobile-web/file-list-presentation.ts

@@ -1,46 +0,0 @@
-import {
-  MobileWebFileEntrySchema,
-  MobileWebFileListResultSchema,
-  type MobileWebFileEntry,
-  type MobileWebFileListResult
-} from './file-operation-contract'
-import { MobileWebBrokerError } from './bridge-operation-error'
-
-export function sanitizeListResult(
-  result: unknown,
-  pageWorkspaceId: string,
-  hostWorkspaceId: string | undefined,
-  limit: number
-): MobileWebFileListResult {
-  if (!isRecord(result) || result.worktree !== hostWorkspaceId || !Array.isArray(result.files)) {
-    throw new MobileWebBrokerError('host_error')
-  }
-  const files = result.files.slice(0, limit).flatMap((value): MobileWebFileEntry[] => {
-    if (!isRecord(value) || typeof value.relativePath !== 'string') {
-      return []
-    }
-    const parsed = MobileWebFileEntrySchema.safeParse({
-      relativePath: value.relativePath,
-      basename: value.relativePath.split('/').at(-1)?.slice(0, 255),
-      kind: value.kind === 'binary' ? 'binary' : 'text'
-    })
-    return parsed.success ? [parsed.data] : []
-  })
-  const totalCount =
-    typeof result.totalCount === 'number' &&
-    Number.isSafeInteger(result.totalCount) &&
-    result.totalCount >= 0
-      ? result.totalCount
-      : result.files.length
-  return MobileWebFileListResultSchema.parse({
-    workspaceId: pageWorkspaceId,
-    files,
-    totalCount,
-    truncated:
-      result.truncated === true || result.files.length > files.length || totalCount > files.length
-  })
-}
-
-function isRecord(value: unknown): value is Record<string, unknown> {
-  return typeof value === 'object' && value !== null && !Array.isArray(value)
-}