feat(docs): automate versioned example imports

[demtario]

Summary

Task: https://app.clickup.com/t/9015210959/DEV-2101

• add a matrix workflow that imports release and next docs buckets, summarizes each branch, and creates a generated-content PR
• resolve imported npm and Angular type dependencies to immutable registry versions
• document CI-owned docs-example generation

Test plan

• pnpm test
• Parse workflow YAML
• Check modified importer JavaScript syntax
• Example PR created by workflow: chore(docs): update versioned docs examples #63

PR intentionally merged into another feature branch, to not break production logic with partial changes.

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Note

Medium Risk
Introduces CI that checks out an external repo, calls npm during imports, and opens PRs with contents:write, but changes are confined to docs-example generation and dependency pinning rather than runtime auth or production app logic.

Overview
Docs example snapshots are now produced in GitHub Actions instead of relying on developers to run the importer locally. A new Import versioned docs examples workflow builds a branch matrix (release bucket from npm handsontable dist-tags.latest → prod-docs/<major.minor>, plus develop → next, or a single branch via repository_dispatch / docs-examples-sync), sparse-checks out handsontable/handsontable docs content per job, runs import-docs.mjs, uploads bucket artifacts, and on success opens or updates an automated PR (chore/docs-example-buckets) with merged output under apps/authoring/public/docs-examples/. Job summaries report import outcome, HOT version, and per-framework counts.

The importer pins every discovered extra npm dependency (and Angular @types/* for papaparse/moment) to concrete registry dist-tags.latest versions via shared resolveNpmPackageVersion; failures are fatal and generated package.json files no longer contain "latest". runner/docs/docs-examples.md documents CI ownership, tokens, and local-only debugging.

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