fix: export every prompt by paging instead of truncating at 10000

/prompt_manager/export fetched a single page of 10000 prompts and
silently dropped the rest. It now walks the table in EXPORT_PAGE_SIZE
pages (1000) inside one executor job until a short page is returned.

py/api/prompts.py

@@ -11,6 +11,10 @@ from aiohttp import web
 MAX_PAGE_LIMIT = 500
 MAX_PAGE_OFFSET = 10_000_000
 
+# The export walks the whole table in pages of this size instead of asking
+# for one giant result set (and silently truncating large libraries).
+EXPORT_PAGE_SIZE = 1000
+
 
 def parse_page_params(query, default_limit=50, max_limit=MAX_PAGE_LIMIT):
     """Return ``(limit, offset)`` from a query mapping, clamped to safe bounds.
@@ -1099,10 +1103,20 @@ class PromptRoutesMixin:
                 status=500,
             )
 
+    def _all_prompts_for_export(self):
+        """Every prompt, fetched in EXPORT_PAGE_SIZE pages (blocking)."""
+        prompts, offset = [], 0
+        while True:
+            page = self.db.search_prompts(limit=EXPORT_PAGE_SIZE, offset=offset)
+            prompts.extend(page)
+            if len(page) < EXPORT_PAGE_SIZE:
+                return prompts
+            offset += EXPORT_PAGE_SIZE
+
     async def export_prompts(self, request):
         """Export all prompts to JSON."""
         try:
-            prompts = await self._run_in_executor(self.db.search_prompts, limit=10000)
+            prompts = await self._run_in_executor(self._all_prompts_for_export)
 
             export_data = {
                 "export_date": datetime.datetime.now(datetime.timezone.utc).isoformat(),

tests/test_api_prompts.py

@@ -7,7 +7,7 @@ import os
 import sys
 import tempfile
 import unittest
-from unittest.mock import MagicMock
+from unittest.mock import MagicMock, patch
 
 sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
 
@@ -19,6 +19,7 @@ from aiohttp.test_utils import AioHTTPTestCase  # noqa: E402
 
 from database.operations import PromptDatabase  # noqa: E402
 from py.api import PromptManagerAPI  # noqa: E402
+import py.api.prompts as prompts_module  # noqa: E402
 from py.api.prompts import (  # noqa: E402
     MAX_PAGE_LIMIT,
     MAX_PAGE_OFFSET,
@@ -504,6 +505,30 @@ class TestTagInputValidation(RouteCoverageCase):
         await self._assert_all_400("bad\x00tag")
 
 
+class TestExportPagesThroughAllPrompts(RouteCoverageCase):
+    """GET /prompt_manager/export never truncates: it pages until exhausted."""
+
+    async def test_export_is_complete_beyond_one_page(self):
+        ids = {self._save_prompt(f"export {i}") for i in range(5)}
+        real_search = self.api.db.search_prompts
+        calls = []
+
+        def spy(*args, **kwargs):
+            calls.append((kwargs.get("limit"), kwargs.get("offset")))
+            return real_search(*args, **kwargs)
+
+        self.api.db.search_prompts = spy
+
+        with patch.object(prompts_module, "EXPORT_PAGE_SIZE", 2):
+            resp = await self.client.request("GET", "/prompt_manager/export")
+
+        self.assertEqual(resp.status, 200)
+        data = json.loads(await resp.text())
+        self.assertEqual(data["total_prompts"], 5)
+        self.assertEqual({p["id"] for p in data["prompts"]}, ids)
+        self.assertEqual(calls, [(2, 0), (2, 2), (2, 4)])
+
+
 class TestTagMutationRoutes(RouteCoverageCase):
 
     async def test_rename_rejects_bad_json_and_empty_name(self):