Slim embed tab rendering to cut memory use and restore calculator.

Load only per-tab data for embed fragments, skip exchange capital fetches on tab switches, and harden calculator market imports/timeouts.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/test_instance_embed_context_lib.py

@@ -0,0 +1,28 @@
+from instance_embed_context_lib import embed_render_plan, trade_records_summary
+
+
+def test_embed_fragment_trade_is_light():
+    plan = embed_render_plan("trade", "fragment")
+    assert plan.exchange_capitals is False
+    assert plan.records_rows is False
+    assert plan.records_summary is False
+    assert plan.orders is True
+    assert plan.key_history is False
+
+
+def test_embed_shell_trade_summary_only():
+    plan = embed_render_plan("trade", "shell")
+    assert plan.exchange_capitals is True
+    assert plan.records_summary is True
+    assert plan.records_rows is False
+
+
+def test_embed_records_page_loads_rows():
+    plan = embed_render_plan("records", "fragment")
+    assert plan.records_rows is True
+
+
+def test_full_page_unchanged():
+    plan = embed_render_plan("trade", None)
+    assert plan.records_rows is True
+    assert plan.exchange_capitals is True