Add the default Structured Liquidity KPI grid

[heyinterspace]

Summary

• add reusable KpiGrid and KpiCard shadcn registry components
• standardize square metric cards, comparison badges, tooltips, responsive layout, and loading/unavailable states
• register the KPI surface as a stable default pattern and document the contract for adopters
• explicitly require applications to supply audited values rather than component-level fallback metrics

Validation

• registry generation and schema consistency: passed (82 items)
• adopter registry: passed (9 projects)
• Structured Liquidity artifact typecheck: passed
• Structured Liquidity production build: passed
• full workspace typecheck could not resolve unrelated workspace dependencies from the isolated worktree; the same primary checkout baseline passed before this feature work

[heyinterspace]

IV-172 coordination: the owner has approved a code-only consolidation into Interspace-Ventures/construct, followed by read-only archival of this repository after deployment source verification. This proposal is inventoried in Construct migrations/pending-source-work.json with an unapplied selected-code patch at migrations/pending-patches/structured-2.patch. Excluded assets remain in this original PR for review; this migration does not approve or silently merge the feature. Continue future work in Construct under the Page/Surface ownership protocol in docs/migration-coordination.md. Migration branch: agent/iv-172-code-only.