447112b17f
Completes H2: - comprehensiveness coverage tests: every REGISTRY command form has a hint_id resolving to a hint.cmd.* block, and every runtime error class resolves to a hint.err.* block (enforces ADR-0053 D6) - ADR-0051 keybinding strip advertises F1 in the editing (leads) and default states; +shortcut.hint label; 12 full-panel snapshots re-accepted (status-bar line only) - flip ADR-0053 -> implemented, requirements H2 + A1 -> [x], README 2498 pass / 1 ignored, clippy clean.