Task: Reference the anchor from every instrument

No instrument table checks its trade against the wide trade; each checks the anchor.

• The 52 trading models that reference ores_trading_trades_tbl reference ores_trading_trade_anchors_tbl, generated from the models.
• The ORE import still saves its instruments, and the round trip stays lossless in scope.
• Build, ctest, pgTAP and the local check set pass.

Retarget every instrument's trade reference with a script over the models, regenerate, and fix what the generator assumed about the target.

• retarget_trade_fk.py points the trade_id foreign key of the 52 models that named ores_trading_trades_tbl at ores_trading_trade_anchors_tbl. The wide trade's own model is left as it is.
• The reference stays a trigger check rather than a database foreign key: the tenant purger deletes no instrument rows, so an enforced key would stop a tenant that holds instruments from being purged. The acceptance's purge order covers enforced keys only.
• The generator assumed every trigger-checked target is temporal and filtered on valid_to, which the immutable anchor has no column for. A target whose model is immutable now gets no current-version filter.
• The derived parent seeding in the generated tests assumed an audited, temporal parent with text lookups; the anchor is neither. A script adds the same parent_seed snippet the booking uses to each model, writing the trade's anchor at the column's group path.
• The hand-written instrument tests' shared seed writes an anchor instead of a wide trade.

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.

• Follow-up: the tenant purger deletes no instrument rows and no wide trades. A purge of a tenant that holds trades leaves them behind.

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.

Every instrument and instrument child table now checks its trade against the trade anchor rather than the wide trade. The generator learned that a trigger check against an immutable table reads its row without a current-version filter. The ORE import still saves its instruments, each with its anchor, and the round trip reads as it did before the switch.