more robust import script

README.md

@@ -52,7 +52,26 @@ Preview an import without changing the database:
 python scripts/import_excel.py /path/to/fatima.xlsx
 ```
 
-Add `--apply` to import. The command backs up the existing SQLite file before updating it.
+The preview prints the absolute workbook and database paths, current database
+row counts and date range, discovered workbook values, and overwrite counts.
+Check that the printed database path is the same file used by the production
+app before applying the import.
+
+Add `--apply` to import:
+
+```sh
+python scripts/import_excel.py /path/to/fatima.xlsx --apply
+```
+
+The importer refuses to write if the database is missing, has the wrong schema,
+or the workbook contains no importable data. It creates a consistent SQLite
+backup before writing, reads every imported value back after committing, and
+prints the final row counts and date range. If production uses a non-default
+database location, specify it explicitly:
+
+```sh
+python scripts/import_excel.py /path/to/fatima.xlsx --database /absolute/path/calendar.sqlite --apply
+```
 
 On the iPhone, visit `http://<your-computer-on-the-local-network>:9009/fatima/`.
 Waitress listens on all network interfaces with the command above. For anything