feat(srd): import Madness and Objects references

[jbongaarts]

Summary

• import Short-Term, Long-Term, and Indefinite Madness plus Object AC/HP as five exact reference tables
• add five lookupable Madness/Objects rules with fail-closed section boundaries and exact coverage baselines
• fix 4-5-fragment PDF gutter selection, preserving Objects order and repairing seven interleaved Magic Items A-Z descriptions
• regenerate the canonical SRD pack and update importer/coverage documentation

Verification

• npm run verify:worktree (1250 passed, 3 documented skips)
• npm run audit:rules-pack -- packages/core/data/rules-packs/rules__dnd5e-srd-5.1 (0 suspicious records)
• npm run verify:dnd5e-srd-pack (0 manifest changes; 0 records added/removed/changed versus fresh import)

Bead: loreweaver-uuk