Neutral wording in import docs; portable tool output paths

Import-surface docs and docstrings describe the automation as a
migration script; status-doc references in CHANGELOG/ADR-009/ROADMAP
point at repo files. Screenshot/verify tools write to /tmp/shopdb-shots
(created on import) instead of a machine-specific directory.

shopdb/utils/import_mode.py

@@ -1,6 +1,6 @@
 """Import-mode helpers: let admins replay legacy history through the API.
 
-A migration script (or an LLM driving one) importing the classic ASP shopdb
+A migration script importing the classic ASP shopdb
 needs two things the normal API withholds:
 
   1. Preserve each row's original createddate/modifieddate instead of stamping