Frequently used Odoo pages and services have been marked as read-only where they do not need to change data. This can improve reliability and performance by allowing these requests to be handled more efficiently, with no expected change in user workflows.

First pass on the most used controllers which can be flagged as read-only.

Tax report consistency checks now ignore lines where a tax amount exists but the related base amount is intentionally empty. This avoids misleading warnings in grouped tax reports and makes report review smoother for accounting teams.

We might have a tax amount without a base amount on the report. In that
case, we don't need to check the consistency.

An example of that case will be to do a `Group by: Tax > Account` in the
tax report. The aggregation line will have a deliberate empty net
amount.