revert(mothership): back out function_execute table-mount drain — defer to follow-up

The keyset CSV drain for inputTables fixed the 100-row truncation but
introduced an unbounded in-memory materialization: a large table (e.g.
enterprise 1M-row) is drained whole into the web-container heap before
the 50MB mount check runs, risking OOM. Reverting to main's behavior
(100-row mount) for now; the proper fix (incremental byte-bound +
filter/limit/columns selection, or by-reference signed-URL fetch) is
deferred to a separate effort so this PR can ship the user_table speed
work (C/D/E) without the memory regression.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: TheodoreSpeaks

apps/sim/lib/copilot/tools/handlers/function-execute.test.ts

@@ -3,10 +3,7 @@ import { decodeVfsPathSegments, encodeVfsPathSegments } from '@/lib/copilot/vfs/
 import { resolveWorkflowAliasForWorkspace } from '@/lib/copilot/vfs/workflow-alias-resolver'
 import { isPlanAliasPath, workflowAliasSandboxPath } from '@/lib/copilot/vfs/workflow-aliases'
 import { isMothershipBetaFeaturesEnabled } from '@/lib/core/config/feature-flags'
-import { buildNameById, rowDataIdToName } from '@/lib/table/column-keys'
-import { toCsvRow } from '@/lib/table/export-format'
-import { getTableById, listTables, selectExportRowPage } from '@/lib/table/service'
-import type { TableDefinition } from '@/lib/table/types'
+import { getTableById, listTables, queryRows } from '@/lib/table/service'
 import { listWorkspaceFileFolders } from '@/lib/uploads/contexts/workspace/workspace-file-folder-manager'
 import {
   fetchWorkspaceFileBuffer,
@@ -65,44 +62,6 @@ async function resolveTableRef(
   return tablePathLookup?.get(tableName) ?? null
 }
 
-const TABLE_MOUNT_PAGE_SIZE = 5000
-
-/**
- * Serializes a cell for a sandbox CSV mount. Unlike export downloads this skips
- * formula neutralization — the CSV is consumed by code, and a prefixed `'`
- * would corrupt values.
- */
-function formatMountCsvValue(value: unknown): string {
-  if (value === null || value === undefined) return ''
-  if (value instanceof Date) return value.toISOString()
-  if (typeof value === 'object') return JSON.stringify(value)
-  return String(value)
-}
-
-/**
- * Serializes a full table to CSV for a sandbox mount. Walks the keyset export
- * reader page by page so every row is included (`queryRows` with defaults
- * silently truncated mounts to its 100-row page and paid for a count and
- * execution metadata the CSV never used), and remaps stored column-id keys
- * back to display names so headers line up with cell values.
- */
-async function buildTableCsvForMount(table: TableDefinition): Promise<string> {
-  const nameById = buildNameById(table.schema)
-  const headers = table.schema.columns.map((c) => c.name)
-  const lines = [toCsvRow(headers)]
-  let after: { position: number; id: string } | null = null
-  while (true) {
-    const page = await selectExportRowPage(table, after, TABLE_MOUNT_PAGE_SIZE)
-    for (const row of page) {
-      const data = rowDataIdToName(row.data, nameById)
-      lines.push(toCsvRow(headers.map((header) => formatMountCsvValue(data[header]))))
-    }
-    if (page.length < TABLE_MOUNT_PAGE_SIZE) return lines.join('\n')
-    const last = page[page.length - 1]
-    after = { position: last.position, id: last.id }
-  }
-}
-
 async function resolveInputFiles(
   workspaceId: string,
   inputFiles?: unknown[],
@@ -288,41 +247,55 @@ async function resolveInputFiles(
     const tablePathLookup = hasTablePathRefs
       ? new Map((await listTables(workspaceId)).map((table) => [table.name, table]))
       : undefined
-    const tableMounts = await Promise.all(
-      inputTables.map(async (tableRef) => {
-        const tableId =
-          typeof tableRef === 'string'
-            ? tableRef
-            : tableRef && typeof tableRef === 'object'
-              ? (tableRef as CanonicalTableInput).tableId || (tableRef as CanonicalTableInput).path
-              : undefined
-        if (!tableId) return null
-        const table = await resolveTableRef(tableId, tablePathLookup)
-        if (!table || table.workspaceId !== workspaceId) {
-          throw new Error(
-            `Input table not found: "${tableId}". Pass the table id (tbl_...) from tables/{name}/meta.json, or a tables/{name}/meta.json path.`
-          )
-        }
-        const csvContent = await buildTableCsvForMount(table)
-        const sandboxPath =
-          typeof tableRef === 'object' && tableRef !== null
-            ? (tableRef as CanonicalTableInput).sandboxPath
+    for (const tableRef of inputTables) {
+      const tableId =
+        typeof tableRef === 'string'
+          ? tableRef
+          : tableRef && typeof tableRef === 'object'
+            ? (tableRef as CanonicalTableInput).tableId || (tableRef as CanonicalTableInput).path
             : undefined
-        return {
-          path: sandboxPath || `/home/user/tables/${table.id}.csv`,
-          content: csvContent,
-        }
-      })
-    )
-    for (const mount of tableMounts) {
-      if (!mount) continue
-      if (totalSize + mount.content.length > MAX_TOTAL_SIZE) {
+      if (!tableId) continue
+      const table = await resolveTableRef(tableId, tablePathLookup)
+      if (!table || table.workspaceId !== workspaceId) {
         throw new Error(
-          `Mounting table "${mount.path}" would exceed the ${MAX_TOTAL_SIZE / 1024 / 1024}MB total mount limit. Mount fewer or smaller tables.`
+          `Input table not found: "${tableId}". Pass the table id (tbl_...) from tables/{name}/meta.json, or a tables/{name}/meta.json path.`
+        )
+      }
+      const rows = await queryRows(table, {}, 'copilot-fn-exec')
+
+      const allKeys = new Set(table.schema.columns.map((column) => column.name))
+      for (const row of rows.rows ?? []) {
+        if (row.data && typeof row.data === 'object') {
+          for (const key of Object.keys(row.data as Record<string, unknown>)) {
+            allKeys.add(key)
+          }
+        }
+      }
+      const headers = Array.from(allKeys)
+      const csvLines = [headers.join(',')]
+      for (const row of rows.rows ?? []) {
+        const data = (row.data || {}) as Record<string, unknown>
+        csvLines.push(
+          headers
+            .map((h) => {
+              const val = data[h]
+              const str = val === null || val === undefined ? '' : String(val)
+              return str.includes(',') || str.includes('"') || str.includes('\n')
+                ? `"${str.replace(/"/g, '""')}"`
+                : str
+            })
+            .join(',')
         )
       }
-      totalSize += mount.content.length
-      sandboxFiles.push(mount)
+      const csvContent = csvLines.join('\n')
+      const sandboxPath =
+        typeof tableRef === 'object' && tableRef !== null
+          ? (tableRef as CanonicalTableInput).sandboxPath
+          : undefined
+      sandboxFiles.push({
+        path: sandboxPath || `/home/user/tables/${table.id}.csv`,
+        content: csvContent,
+      })
     }
   }