Task: Seed the sensitivity shift families

The store seeds the sensitivity documents the ladder reports bind, transcribed from the ORE examples and grounded in xsd/sensitivity.xsd.

• A document per risk class exists for the classes the store holds market data for, and each states its shift type, shift size, scheme and bucket list.
• The .1 family and the basis-point family share one document per risk class, selected through the keyed ShiftSize, ShiftType and ShiftScheme entries.
• Every seeded document validates against external/ore/xsd/sensitivity.xsd.
• A document round trips through the store without losing a block or a keyed override.

(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.

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.

• Greek ladder reports — the design this task builds.