refactor(#447): move shop-charts.json/ontime-charts.json to Dashboard v2

[BorisTyshkevich]

Summary

• shop-charts.json and ontime-charts.json move to portable-bundle v2 / Dashboard document v2, dropping their curated filters arrays in favor of inferred Variables — completing the "phase 3" example rewrite spec-examples.test.js had been pinning them against, following clickhouse-operations.json's earlier move (feat(#447): inferred Dashboard Variables, replacing the curated filter model (phase 1) #458 follow-up).
• Audited every from/to/country/category/carrier/origin filter's targets list against the {name:Type} placeholders actually present in each tile's SQL: they already matched exactly, so this is a mechanical model migration with no change to which variables apply to which tiles.
• Fixed a latent bug in build-ontime-charts.mjs: it wasn't threading version through to writeExampleBundle, so regenerating the file would have silently reverted it to v1.
• Updated examples/mjs/normalize-examples.mjs, examples/mjs/README.md, and tests/unit/spec-examples.test.js to reflect the new pinned versions.

Test plan

• node examples/mjs/normalize-examples.mjs --check
• npx tsc --noEmit
• node build/compile-json-schemas.mjs --check
• node build/check-boundaries.mjs
• TZ=America/New_York npx vitest run --config tests/vitest.config.ts (5935/5935 passing)

🤖 Generated with Claude Code

https://claude.ai/code/session_011sMwR4BHM85MExSBYXzTYj

[BorisTyshkevich]

Added a follow-up commit: the v2 migration left every Array/enum-shaped variable (country/category, carrier/origin, user/query_kind/exception_code/query_hash/metric/is_initial_query) on bare freeform-text input, with no variableConfigs. Traced back through git history to the pre-#447 curated-filter option-source queries (shop-filter-options, ontime-filter-options, gco-filter) and ported each into its own variableConfigs[name].sql under the new two-String-column (value, then label) contract — restoring the searchable (multi-)select these variables had before #447.

Verified the full compiled option batch (compileVariableOptionBatch) builds cleanly for all three dashboards, and every new option SQL passes optionSqlDiagnostics locally. Not run against a live ClickHouse server (sandboxed environment has no reachable cluster) — worth a manual smoke test against system.query_log before merge, since the clickhouse-operations.json queries in particular depend on real server activity/log retention.