[P2] Reconcile #618: close as declined or actually split github.ts

[itsmiso-ai]

Problem

Issue #618 was closed with acceptance criteria unmet — github.ts is still 1049 lines and the domain facades are re-export wrappers that add no value. This creates confusion about what "extracted" means.

Evidence

• src/lib/github.ts — 1049 lines
• 4 facade files with export * from "./github"

Acceptance

Either close #618 as "sufficient" and document the decision in the issue, or re-open it and split the module into domain files under 400 lines each.

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Decomposed from #648 (Weekly tech debt audit: misospace/dispatch - 2026-07-22).