Add advanced Context helpers guide

[dahlia]

Background

The manual already covers several advanced Context and RequestContext methods, but the material is spread across multiple pages: routeActivity() in the inbox guide, getSignedKeyOwner() in the access control guide, and remote-lookup helpers split across the WebFinger and NodeInfo pages. This makes the higher-level Context API harder to discover than it should be.

Changes

• Add docs/manual/context-advanced.md, a dedicated guide that gathers all the advanced Context helpers in one place, with usage examples and a quick-reference table:
  • parseUri()
  • routeActivity() (including its security/trust semantics)
  • getSignedKey() and getSignedKeyOwner() (including the instance actor / mutual authorized fetch pattern)
  • getDocumentLoader() and authenticated document loading
  • getActorKeyPairs()
  • lookupObject(), lookupWebFinger(), lookupNodeInfo(), and traverseCollection()
  • RequestContext.request and RequestContext.url
• Add a cross-link from docs/manual/context.md to the new guide.
• Add the new page to the manual navigation in docs/.vitepress/config.mts.

Protocol-specific caveats (authorized fetch, WebFinger resolution, NodeInfo discovery, etc.) are kept in their existing pages; the new guide provides concise summaries and links back to those pages for deeper coverage.

Closes #670

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: ASSERTIVE

Plan: Pro

Run ID: 468e02b3-94a5-48b3-a44b-d43b4eb07993

📥 Commits

Reviewing files that changed from the base of the PR and between 12c6288 and f48ba8f.

⛔ Files ignored due to path filters (1)

• deno.lock is excluded by !**/*.lock

📒 Files selected for processing (4)

• .zed/settings.json
• docs/.vitepress/config.mts
• docs/manual/context-advanced.md
• docs/manual/context.md

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📝 Walkthrough

Walkthrough

This PR adds comprehensive documentation for advanced Context and RequestContext helpers through a new dedicated guide page. It updates the existing Context documentation to cross-link to the new guide, adds a navigation entry to the documentation site, and updates IDE configuration settings.

Changes

Cohort / File(s)	Summary
Documentation docs/manual/context-advanced.md, docs/manual/context.md, docs/.vitepress/config.mts	New advanced Context guide page documenting URI parsing, activity routing, signature verification, authenticated fetching, actor key introspection, remote object/WebFinger/NodeInfo lookups, and collection traversal. Updated main context page with cross-link. Added navigation entry.
Repository Configuration .zed/settings.json	Added Markdown language configuration with external formatter (hongdown) and language server allow/deny list.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~12 minutes

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely summarizes the main change: adding a dedicated advanced Context helpers guide to consolidate scattered documentation.
Description check	✅ Passed	The description is directly related to the changeset, providing background on the documentation gap and detailing all changes made: the new guide, cross-links, and navigation updates.
Linked Issues check	✅ Passed	All coding requirements from issue #670 are met: the new context-advanced.md guide covers all specified helpers with examples and links, cross-links are added to context.md, navigation is updated in config.mts, and protocol-specific caveats remain on their original pages.
Out of Scope Changes check	✅ Passed	All changes are directly aligned with issue #670 objectives. The new Markdown language configuration in .zed/settings.json appears unrelated to the documentation objectives but is a minor configuration addition that does not compromise the PR's primary scope.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[gemini-code-assist]

Code Review

This pull request introduces a new documentation page, "Advanced context helpers," which provides detailed guidance on URI parsing, manual activity routing, signature introspection, and authenticated fetching. It also updates the project's Markdown formatting configuration and refreshes numerous dependencies in the lockfile. Feedback was provided to improve a code example in the new documentation by using optional chaining to safely handle cases where an actor might not have any registered key pairs.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ All tests successful. No failed tests found.

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