Task: Add the run detail tables

Each kind of run records its own facts in a detail table keyed by the run.

• Compression, allocation, merge, roll, sweep and bulk book move detail tables exist, each keyed by the process run with an enforced foreign key.
• The process named by a run states which detail table, if any, a run of that process carries; a pgTAP test refuses a detail row of the wrong process.
• No detail table is keyed by a trade activity: the activity is the stamp on an amendment, and the run is the parent here.

(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.