Dev accounts for every provider lane

Goal: every provider lane can be verified on dev through the console, without re-signing accounts by hand. - Export/Import an account between control planes in the console (API-key accounts re-encrypted for the target; OAuth either carries a working token or the import says it needs sign-in). The key never appears in UI, download names or logs. - Give dev's Gmind org one account per lane (Claude subscription, Claude Jaah/Bedrock, Codex OAuth, Codex API key, Antigravity API key, ACP-registry agent), auto-assign off; a lane a human must supply is recorded as such. - Run one task per lane and record its id; for Antigravity API key also the AC4 chat/steer/session checks and the Providers ACP switch OFF→ON round trip. Out of scope: changing how sign-in works; NodeLink token sharing. Done means: an API-key account exported from one CP runs a task after import on another; each lane has a settled dev task id or a recorded human-only reason.

Account Export/Import shipped (#6630 merged, deploy 39776642602 green). Dev: 5248 ran on an imported DeepSeek key (dev→slot console→dev); Antigravity API key 5246 (ACP) + 5247 (switch OFF→legacy, restored ON). Human-only: Claude sub, Codex OAuth/API key; Bedrock + ACP registry blocked by a Gmind override (#9061). Memory: used mem-23382, mem-15203; proposed 0.