PR #158 review-leftover: The upstream probe nests the fork's fingerprint-plus-e-mail composition inline, [995f44f665ef] #160

[review-leftover] #158

• apps/server/src/provider/antigravityUsageLimits.ts:295 The upstream probe embeds the fork's fingerprint-plus-e-mail composition in a seven-line flatMap/map block. Move that composition into a fork helper and replace the inline block with one call.