Product content (changelog / docs)

Mainark views and (later) edits product documentation that lives in each product's git repository. Git remains the source of truth. There is no docs CMS or snapshot ingest pipe.

Fulreach contract: product repo docs/ops/mainark-docs-contract.md.

Design

Concern	Choice
Read/write	GitHub Contents + Git Data API (`GITHUB_PAT` on orchestrator only)
Auth	Every `/api/content/*` route requires bearer `MAINARK_API_TOKEN`; web uses session cookie → Next proxy
Config	`src/content/productContentConfig.ts` — paths + branches per `productId`; repo URL from existing Mainark config
Isolation	Never uses agent worktrees or `REPO_PATH`

Phases

P0 — Changelog timeline (GET /api/content/:product/changelog, UI /changelog)
P1 — Docs browser (/content): Fumadocs-like meta.json nav, safe non-executing MDX preview, search corpus cached by commit SHA
P2 — MDX source editor (/content/edit?path=) → feature branch from the tip commit whose file blobSha matched → PR into prTargetBranch (no auto-merge)

SHAs

API responses distinguish:

blobSha — Contents API file object sha (optimistic concurrency for edits)
commitSha / baseCommitSha — git commit the file was read at / branch base