Consolidate examples into three flagship dashboards

[BorisTyshkevich]

Summary

Consolidate the accumulated non-Iceberg example fixtures into three focused, responsive flagship dashboards:

• On-time flights — 7 visible analytical tiles, KPI band, shared 2023 range, and carrier/origin multiselects
• Shop analytics — 7 visible business tiles backed by shop-demo.sql, with targeted country/category filters
• ClickHouse Operations — 16 operator-first tiles plus the remaining downloaded operational queries as untiled Library entries

All Iceberg artifacts remain unchanged except for a stale generator comment.

What changed

• Import and curate the downloaded Operations bundle as examples/clickhouse-operations.json
• Retire the standalone KPI, logs, query-log, System Explorer, and earlier Grafana-port fixtures
• Extend example authoring helpers for grafana-grid@1, explicit sizing/order, authored filters/defaults/targets, and complete flow@1 fallbacks
• Preserve chart schema keys and update the live On-time schema-key generator
• Add consistent Array(T)/ has(...) multiselect contracts across compatible consumers
• Rewrite the examples documentation around the three flagship dashboards
• Expand example validation for canonical filenames, layout fallbacks, references, schema keys, and multiselect type agreement

Impact

The examples directory now presents three discoverable end-to-end dashboards instead of many overlapping feature fixtures. Secondary analyses remain available in each bundle's Library without adding visual dashboard clutter. Production schemas and runtime APIs are unchanged.

Validation

• node examples/mjs/normalize-examples.mjs --check
• npm test — 166 test files, 5,015 tests; coverage gate passed
• npm run build
• git diff --check

External QA still required

• Live On-time regeneration needs a configured clickhouse-client --connection antalya profile
• Shop and Operations tile smoke tests need suitably privileged ClickHouse clusters
• Browser visual QA could not run in the authoring session because no browser backend was available