v1.3.0: Codebase cleanup -- dead code removal and compression

Major internal refactor removing 13,000+ lines of dead code and compressing boilerplate across the workspace.

Highlights

• Removed dead cognitive module, brain oracle/pca/reasoning, guard module, quota_sync, skills/registry, skills/patch, and 20+ dead functions
• route! macro compresses 477 route entries (-4,094 lines)
• tenant_migration_sql! macro replaces 59 wrapper functions (-340 lines)
• Section divider compression across all crates
• Default impls for StoreRequest/SearchRequest
• Placeholder types.rs files removed, require_registry helper extracted
• CI clippy and deny fixes

205 files changed, 3,921 insertions, 17,148 deletions. Net: -13,227 lines.