Add Create Test Shipment (Email SKU) for testing the return-label flow, plus test-mode/store_id investigation notes

Adds synthetic source="test" tickets (create_test_shipment_order/delete_test_shipments)
carrying a company's real emailed-return-label SKU, so Step 1/Step 2 can be exercised
against the sandbox without a real JIRA ticket or risking a real customer's. Gated to
Test Mode - the same flow against production would create a real paid shipment.

CLAUDE.md also captures this session's ShipStation sandbox findings: store_id is
schema-optional but empirically required for label visibility, the newer ship15 web UI's
URL is NOT the se- store ID (confirmed via direct probe - different failure shape than a
wrong-but-well-formed ID), and two separate test stores/carriers are needed per company,
mirroring production.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

app/workers.py

@@ -9,11 +9,13 @@ pattern rather than blocking the UI.
 from __future__ import annotations
 
 import datetime as dt
+import uuid
 from typing import List, Tuple, TypedDict
 
 from PyQt6.QtCore import QThread, pyqtSignal
 from sqlalchemy import select, delete
 
+from app import config
 from app.database import get_session
 from app.models import Order
 from app.schedule import get_cutoff_time, is_past_cutoff_today
@@ -301,6 +303,97 @@ def reset_local_database() -> int:
         session.close()
 
 
+def _emailed_label_sku_for_company(company: str) -> str:
+    """Picks whichever configured EMAILED_LABEL_SKUS entry actually
+    resolves to the given company via COMPANY_SKU_MAP, rather than
+    hardcoding SH007/OK012 - stays correct if either setting changes."""
+    from app.companies import parse_mapping, resolve_company_by_sku
+    from app.return_labels import get_emailed_label_skus
+
+    sku_map = parse_mapping(config.get("COMPANY_SKU_MAP", config.DEFAULT_COMPANY_SKU_MAP))
+    for sku in sorted(get_emailed_label_skus()):
+        if resolve_company_by_sku(sku, sku_map) == company:
+            return sku.upper()
+    return ""
+
+
+def create_test_shipment_order(company: str) -> Order:
+    """
+    Creates a synthetic, non-JIRA Order row carrying that company's
+    configured emailed-return-label SKU, purely so the existing "Create
+    Return Label" flow (return_label_dialog.py + shipstation_send.py) can
+    be exercised end-to-end - dummy shipment, then real return label -
+    against a throwaway ticket instead of risking a real customer's.
+
+    source="test" keeps this completely separate from real JIRA rows:
+    save_orders() only ever matches on source == "jira"/"shipstation", so
+    Import from JIRA can never touch or overwrite one of these, and
+    delete_test_shipments() cleans them up by that same marker.
+
+    status="Created" so it lands on the Active tab like a real open
+    ticket would - that's where staff would naturally go to select it and
+    run Create Return Label.
+    """
+    sku = _emailed_label_sku_for_company(company)
+    if not sku:
+        raise ValueError(
+            f"No EMAILED_LABEL_SKUS entry resolves to '{company}' via COMPANY_SKU_MAP - "
+            "check both settings."
+        )
+
+    ticket_number = f"TEST-EMAIL-{uuid.uuid4().hex[:8].upper()}"
+
+    order = Order(
+        source="test",
+        external_id=ticket_number,
+        ticket_number=ticket_number,
+        company=company,
+        skus=[sku],
+        line_items=[{"sku": sku, "item_name": "TEST - Emailed Return Label"}],
+        shipping_info={
+            "name": "TEST ORDER - DO NOT SHIP",
+            "phone": "555-555-5555",
+            "email": "",
+            "address1": "123 Test St",
+            "address2": "",
+            "city": "Austin",
+            "state": "TX",
+            "zip": "78701",
+        },
+        creator="Test Shipment Generator",
+        assignee="",
+        description=(
+            "Synthetic test order created via Data > Create Test Shipment (Email SKU) - "
+            "not a real ticket. Safe to delete with Data > Delete Test Shipments."
+        ),
+        summary=f"TEST - Emailed Return Label ({company})",
+        status="Created",
+        source_created_at=dt.datetime.now(),
+    )
+
+    session = get_session()
+    try:
+        session.add(order)
+        session.commit()
+    finally:
+        session.close()
+
+    return order
+
+
+def delete_test_shipments() -> int:
+    """Removes every synthetic order created by create_test_shipment_order()
+    (source == "test") - real JIRA-sourced rows are untouched, since those
+    always have source == "jira"."""
+    session = get_session()
+    try:
+        result = session.execute(delete(Order).where(Order.source == "test"))
+        session.commit()
+        return result.rowcount or 0
+    finally:
+        session.close()
+
+
 def load_all_orders() -> List[Order]:
     session = get_session()
     try: