fix(redirects): Restore GitHub Enterprise docs URL

[sansynx]

DESCRIBE YOUR PR

Fixes #19601

The reported GitHub Enterprise URL returns 404. Its installation instructions are on the GitHub integration page, so this adds a permanent redirect there. No content changes.

Validation:

• Confirmed the reported URL returns 404 and the destination returns 200
• Exercised the redirect through Next.js's config-testing helper: 308 response, preserved query string, no redirect at the destination
• 53 redirect-related tests passed
• Prettier and git diff --check passed

AI assistance was used to prepare and check this change.

IS YOUR CHANGE URGENT?

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PRE-MERGE CHECKLIST

• Checked Vercel preview for correctness, including links
• PR was reviewed and approved by any necessary SMEs (subject matter experts)
• PR was reviewed and approved by a member of the Sentry docs team

LEGAL BOILERPLATE

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[cursor]

This change adds a permanent redirect from a 404 docs URL to the page with its install steps. The plan checks that redirect, nearby 404s, destination page loads, and client errors. An issue escalates when the old URL still 404s or when 404s or errors rise.

Services: sentry-docs.

Mention @change-monitor in a comment to update the plan.

Plan

What changed

Requests to /integrations/source-code-mgmt/github-enterprise/ now send a permanent redirect to /integrations/source-code-mgmt/github/. The install steps already live on that destination page. sentry-docs must deploy before this redirect is live. The new rule is in the user docs redirect list only. Developer docs do not receive this rule. This pull request claims to fix issues/19601.

Risk

If the redirect is missing, users still see the not-found page on the old URL. If the redirect table fails to load, other docs redirects can 404 too. If the destination page breaks, redirected users land on a failing GitHub install page.

Intended effect

Confirmed means the old URL no longer renders the not-found page and traffic reaches the GitHub install page. Absent means middleware still logs that old path at the baseline rate and sampled pageloads of that URL continue. The edge 308 itself is not in Sentry. Use the drop in not-found pageloads on the old URL as the reachable proof.

Traces are sampled at 30 percent. Treat pageload counts as sampled volume, not full traffic.

Signal	Baseline	Rule	Source
404 on /integrations/source-code-mgmt/github-enterprise/	The live URL still returns the not-found page. Sampled pageloads with http.url matching that path: 10 in 2026-09-26T05:46:00Z to 2026-10-03T05:46:00Z. Middleware logs Middleware request processed: /integrations/source-code-mgmt/github-enterprise/: 17 in that 7d window, 6 in 2026-10-02T05:46:00Z to 2026-10-03T05:46:00Z.	After deploy, sampled pageloads of the not-found page on that path must fall below 10 per 7d and stay near zero. Middleware hits on that exact path should fall below 17 per 7d. Hold that drop. absent is a live not-found page plus middleware hits still near 17 per 7d.	Sentry org sentry project docs. Pageload query: span.op:pageload http.url:*integrations/source-code-mgmt/github-enterprise* environment:production. Log query: message:"Middleware request processed: /integrations/source-code-mgmt/github-enterprise/" environment:production. Fixes issues/19601
GitHub install page pageloads	Sampled span.op:pageload with http.url matching /integrations/source-code-mgmt/github and not github-enterprise: 27 in 2026-10-02T05:46:00Z to 2026-10-03T05:46:00Z. p95 duration 7.1s.	Count should hold near 27 per 24h or rise. absent is destination pageloads falling to zero while the old URL still 404s.	Sentry org sentry project docs. Query: span.op:pageload AND http.url:*integrations/source-code-mgmt/github* AND !http.url:*github-enterprise* AND environment:production

Regression watch

A broken redirect table would 404 other docs URLs. A broken destination would fail the GitHub install page. Watch sibling source-code-mgmt pageloads on the same redirect list.

Signal	Baseline	Rule	Source
Site 404 rate docs.page.not_found / docs.page.load	102 not-found and 14033 page loads in 2026-10-02T05:46:00Z to 2026-10-03T05:46:00Z, rate 0.73%. 829 not-found and 119509 page loads in 2026-09-26T05:46:00Z to 2026-10-03T05:46:00Z, rate 0.69%. SCM two-segment path integrations/source-code-mgmt was 5 of 102 not-found in 24h and 23 in 7d.	Hold 404 rate in 0.69-0.73%. Escalate when the rate rises above that band while page loads stay near 14000 per 24h. A small drop in the SCM 404 slice is expected. A site-wide 404 spike is not.	Sentry org sentry project docs. Queries: metric.name:docs.page.not_found environment:production and metric.name:docs.page.load environment:production
Production error events vs page loads	148 error events and 14033 page loads in 2026-10-02T05:46:00Z to 2026-10-03T05:46:00Z, about 1.05 errors per 100 loads. The 7d window has 12096 errors against 119509 loads, so error volume is bursty. Use the 24h pair as the recent watch.	Escalate when 24h errors rise several times above 148 while page loads stay near 14000. Do not treat the 7d error total as a tight band.	Sentry org sentry project docs. Errors query: environment:production on the errors dataset with count().
GitHub install page p95 pageload duration	7.1s p95 from 27 sampled pageloads in 2026-10-02T05:46:00Z to 2026-10-03T05:46:00Z.	Hold p95 near 7.1s. Escalate when p95 rises far above 7.1s or sampled count falls to zero.	Same GitHub pageload query as Intended effect
GitLab sibling pageloads	Sampled pageloads with http.url matching /integrations/source-code-mgmt/gitlab: 13 in 2026-10-02T05:46:00Z to 2026-10-03T05:46:00Z. p95 duration 2.3s.	Hold count near 13 per 24h and p95 near 2.3s. Escalate when count falls to zero or p95 rises far above 2.3s.	Sentry org sentry project docs. Query: span.op:pageload http.url:*integrations/source-code-mgmt/gitlab* environment:production

Not observable

Sentry does not record the CDN 308 status for this Next.js redirect. The executor cannot count 308 responses from this connector. docs.page.not_found only stores the first two path segments, so it cannot isolate this URL from other integrations/source-code-mgmt 404s. Markdown export requests for this path may miss the Next.js redirect and stay uncounted here.