fix(oauth): point proxy landing page to OAuth docs

[rafaeelaudibert]

Problem

The OAuth proxy's root route returns a plain-text landing message, but it linked to the MCP docs (https://posthog.com/docs/model-context-protocol). This is the OAuth proxy, so the link should point to PostHog's OAuth integration docs. The message also used an em-dash, which rendered as mojibake under the text/plain response.

Changes

• Point the landing page link to https://posthog.com/docs/api/oauth.
• Replace the em-dash with a plain hyphen so the text renders cleanly.

How did you test this code?

I'm an agent. The existing tests/router.test.ts assertions (content-type contains text/plain, body contains PostHog OAuth Proxy) remain satisfied by inspection. I was unable to execute the vitest suite in this environment because the service's node_modules are not installed here.

Automatic notifications

• Publish to changelog?
• Alert Sales and Marketing teams?

Docs update

🤖 Agent context

Authored with Claude Code. The task was to repoint the OAuth proxy landing route from MCP docs to OAuth docs and fix the em-dash. I located the correct OAuth docs URL (/docs/api/oauth) via the PostHog docs search, then switched the em-dash to a plain hyphen at the user's request. Left the genuinely MCP-related references in services/mcp/ and the OAuth metadata service_documentation field untouched, since those are not the landing route in question.

[greptile-apps]

_{Reviews (1): Last reviewed commit: "fix(oauth): point proxy landing page to ..." | Re-trigger Greptile}

[stamphog]

The change is a trivial URL update in the OAuth proxy landing page response, but it touches auth infrastructure (deny-listed) and has zero reviews. Request a review from a team member familiar with the OAuth proxy before merging.

[deployment-status-posthog]

Deploy status

Environment	Status	Deployed At	Workflow
dev	✅ Deployed	2026-06-01 21:12 UTC	Run
prod-us	✅ Deployed	2026-06-01 21:29 UTC	Run
prod-eu	✅ Deployed	2026-06-01 21:33 UTC	Run