Task: Remove the last xsdcpp references

No file outside the agile pages names xsdcpp or a script it used.

• git grep -i xsdcpp finds only doc/agile
• The memory and the runbook describe how a money member keeps its digits today

Search the tree outside the agile pages for xsdcpp and for the scripts and types it produced. Delete a page that only describes the old tool. Rewrite any other mention to the current state.

(Implementation strategy. Written when work starts; key decisions are distilled into the parent story's * Decisions at close, but the plan itself stays — it is the historical record of what we did.)

Every number this task claims about a tree, with the command that produced it and the commit it was measured at. A number without both is not a measurement, because a clean-up record describes a tree and trunk moves under a branch: a consumer count, a gate's component count and a suite's size all change with no code changing, and the reader of a bare number cannot tell which tree it came from. Where the raw output matters, put it in an evidence/ file beside the task and name that file in the Command column.

• Deleted: doc/analysis/ore_xsd_schema_gaps.md and doc/knowledge/architecture/ore_numeric_leaf_setters.txt. Both described the old tool only.
• Rewritten to the current state: the memory on exact decimals, the runbook step that carries the digits, the section of the exact numbers page on the ORE boundary, three code comments, the evidence file header and one line of each of two plans.
• The agile pages keep their mentions. They are the record of the work.

Manual QA scenarios (scaffolded via compass add test_scenario) that verify this task. Link new ones here as they're created; the scenario doc itself links back via its "Verifies task" field.

No file outside doc/agile names xsdcpp or a script it used.