Task: Fix the three shared codegen template defects

Close G04. Three defects live in shared templates and so affect every component: <chrono> is not emitted with the timestamp field, the handler's per-method doc claims a permission check that the read verbs do not make, and the generated operator== doc narrates edit history.

• Each defect is fixed in its template with a regression test in the codegen suite.
• The affected components are regenerated and the drift gates are clean.
• G04 passes for ores.reporting.

(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.)

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.