P1: Cross-cluster correlation query

[gnanirahulnutakki]

Phase 1 — the differentiator demo. Implement a cross-cluster correlation query the fleet model makes trivial and single-cluster tools cannot answer.

Tasks

• Query API: "every cluster where deployment X is unhealthy" (and similar)
• Results span both spokes, tenant-scoped, with stale clusters flagged
• UI/CLI/MCP-read surface to run it (thin)

Acceptance

• One query returns a correct cross-cluster answer over ≥ 2 spokes with staleness flagged.

Refs: CHARTER §4, ARCHITECTURE §4.1.

[gnanirahulnutakki]

Local CLI/TUI portion landed in PR #53 (merge 285596a): sith correlate deploy/<name> status!=Healthy returns correct cross-cluster cache-backed answers, preserves stale last-known rows, and is proven across two live Kind contexts plus one unreachable context. PR CI 29126884226 and post-merge dev CI 29127147972 are green. Keeping this issue open for the remaining MCP-read surface and later tenant/spoke path.

[gnanirahulnutakki]

Delivered in PR #102 and merged to dev as 770e265. Exact post-merge CI 29188610480 passed all core/two-kind and release gates.