Add context7.json, tag code fences, refresh Context7 on push

[ProxiBlue]

What this does

These docs are already indexed by Context7 as /mage-os/devdocs. Context7 feeds library documentation to AI coding assistants (Cursor, Claude Code, Copilot and others). This PR makes Context7 read the repo on purpose rather than with its defaults.

No documentation prose changes. Everything here is metadata or config.

1. Add context7.json

• excludeFiles — leaves out documentation.md (nav only), README.md, CODEOWNERS, and the 13 markdown files that are not linked from documentation.md and so render nowhere on devdocs.mage-os.org (acl.md, di.md, db_schema.md, … and the two merged-page leftovers rest-apis-soap-apis.md and the-magento-application-and-service-contracts.md).
  Context7 was indexing these unreachable duplicates instead of the published *_xml pages. In the live index, six File Reference pages (db_schema_xml, fieldset_xml, indexer_xml, menu_xml, webapi_xml, widget_xml) contribute 0 snippets, while their orphan copies supply 44 snippets (8% of the index), each pointing at a path with no published page. The files stay in the repo; three of them hold material their published twin lacks, which should be ported across in a separate content PR before the orphans are deleted.
• description — says what Mage-OS is, that it is compatible with Magento 2 extensions and themes, and that it ships features Magento Open Source lacks (RMA). Context7 matches library lookups on this metadata, not on page content. Context7 documents it as a suggestion it may override, so it's worth measuring after the next parse.
• rules[] — short facts sent to every assistant that looks up Mage-OS, covering things they currently get wrong:
  • the repo.mage-os.org install command
  • PHP 8.3 / 8.4 / 8.5 for 3.x
  • Magento\* namespaces and bin/magento are unchanged
  • db_schema.xml over InstallSchema.php for new modules
  • plugins/observers over preferences
  • RMA ships in core from 3.0.0: mage-os/product-community-edition requires mage-os/module-rma from 3.0.0 through 3.5.0, according to the package metadata on repo.mage-os.org. Assistants today either say you need a third-party extension or suggest building one yourself.

2. Tag 25 untagged code fences

Code blocks with no language make Context7 guess, and its guesses end up as text/APIDOC. Directory trees and ASCII diagrams are now plaintext (the existing repo convention), HTTP request lines http, CLI commands bash, and the php.ini line ini. Only the opening fence line changes; the code inside is untouched.

3. Refresh Context7 on push

.github/workflows/context7-refresh.yml uses Context7's documented refresh call so the index follows main rather than lagging behind it (the last parse was 2026-08-02, before the latest commit). It runs only on mage-os/devdocs and exits cleanly without doing anything until the secret below is set, so it can't fail on forks or before setup.

Needs a maintainer (not doable from a fork)

1. Add the repository secret CONTEXT7_API_KEY (from the Context7 dashboard) to turn on the refresh workflow.
2. Claim /mage-os/devdocs on Context7. It currently shows verified: false. Claiming gives the org an admin panel, higher refresh limits and version management.
3. Ask Context7 to remove or merge /websites/devdocs_mage-os_main. It's a crawl of devdocs.mage-os.org last parsed 2026-02-23, and it outranks this repo's entry on mage-os lookups, so assistants can end up on a copy that is seven months out of date.

Out of scope, as follow-ups

• Port the extra content from extension_attributes.md, routes.md and acl.md into their *_xml pages, then delete the 13 orphan files.
• Eight nav pages have no code blocks at all, so Context7 extracts nothing from them. They need worked examples.
• RMA has no page in the docs.

Findings were measured against the live Context7 index (546 snippets, pulled as JSON) at 291815b.

🤖 Generated with Claude Code

[rhoerr]

Thanks! @DavidLambauer are you able to handle the Context7 key?

[DavidLambauer]

@rhoerr Done, CONTEXT7_API_KEY is set on the repo, so the refresh workflow is live on pushes to main. I'll also claim /mage-os/devdocs on Context7 and follow up with them about merging/removing the stale /websites/devdocs_mage-os_main entry.

[ProxiBlue]

@DavidLambauer Nice.

Let me know, then I can run tests via claude to see if the prior issues I noted had been resolved.

[DavidLambauer]

@rhoerr Could you approve this PR and merge it? Once done, I can trigger the context7 scan

[DavidLambauer]

Re-approving on the current commit. My earlier approval was dismissed when the Context7 claim verification fields (url, public_key) were pushed to this branch; no other content changed.