fix: memory route bug + fast E2E tests under 10 seconds

- Fix recall_personal_facts() call - remove unsupported limit parameter
- Replace 4 slow E2E test files with single fast test file
- All 6 E2E tests complete in ~9 seconds (was 60+ seconds)
- Reuse browser session across tests (module-scoped fixture)
- Combine related checks into single tests
- Add HTTP-only smoke test for speed

src/dashboard/routes/memory.py

@@ -37,7 +37,7 @@ async def memory_page(
         )
     
     stats = get_memory_stats()
-    facts = recall_personal_facts(limit=10)
+    facts = recall_personal_facts()[:10]
     
     return templates.TemplateResponse(
         request,
@@ -88,7 +88,7 @@ async def add_fact(
     store_personal_fact(fact, agent_id=agent_id)
     
     # Return updated facts list
-    facts = recall_personal_facts(limit=10)
+    facts = recall_personal_facts()[:10]
     return templates.TemplateResponse(
         request,
         "partials/memory_facts.html",