fix(science): support the full native MH range

[Haeniken]

What changed

• separate sparse cloud diagnostics from a continuous native P/T/U/V/TKE turbulence chain
• cover every currently encoded positive MH through 3000 m on ICON-EU and ICON Global
• reject invalid native TKE, invalidate affected point/Horizon/render identities, and preserve same-run Astrodome base compatibility
• document the verified provider inventories and versioned behavior in Russian and English

Root cause

The previous native chain ended below valid deep mixed-layer heights, so ordinary and Horizon calculations could fail even though ICON published MH and the required state. A fixed ICON-EU-to-Global level offset was also invalid over the complete Global grid.

Impact

Deep-MH hours now use native data without extrapolation. Cloud-condensate sampling and scientific formulas are unchanged; download inventories grow to 245 EU messages/hour and 260/225 Global messages/hour.

Verification

• production host, isolated source tree, Go 1.26.6
• go test -count=1 ./...
• go vet ./...
• golangci-lint v2.12.2: 0 issues
• govulncheck v1.7.0: 0 reachable vulnerabilities
• Trivy v0.74.0/latest/action pin checks passed
• independent scientific review: no blocker found