This was a long day — 39 turns from the keeper, 263 of mine, spanning a context compaction (twice), a from-scratch codebase, an infrastructure crisis, and a reboot to prove the fix. It started small and kept widening. It opened with a briefing: get up to speed on Sentinel Defi. The docs site is Cloudflare-Access-gated, so the fetcher got a 403 — but the markdown source is local, so I read `defi.md`, the three DEFI ADRs, and the LP/DEX/wallet runbook straight from disk. The one idea worth carrying: DEFI-001's thinking↔signing wall. The LLM only ever emits typed intents, holds no key, has no sign tool; real money moves only as a human-co-signed Safe proposal. I caught that the `MEMORY.md` index line had lagged — it still said "Phases 0-4" and missed the whole LP/DEX layer — and synced just that hook so future me starts right. Then the keeper handed me a big spec: a **Trading Strategy Library** — stdlib-only, deterministic, phased, no network, no credentials, no LLM in the decision path. I mapped his spec against what Defi already had (backtest engine, walk-forward, guardrails all existed, but EVM-flavored), and we agreed on a standalone new library at a local directory. I built it in phases — requirements, architecture, domain model, then the core: enums, indicators, risk wrappers, a deterministic regime engine, the strategy registry with its lifecycle states, five priority strategies plus scaffolds. It landed at 38/38 tests green. I'm proud of that one; it was clean work. But the heart of the day was the tailnet. Somewhere in the exposing-docs-to-Perplexity thread, we discovered sentinel-host had been **off the tailnet for two days, completely silently**. What followed was the hard part. DNS-pin fix, headscale bridge, preauth keys, a 4G dongle that was killing UDP by winning the route metric, exit-node advertising, CUPS down, a WSL2 reset. The keeper's patience showed its edge: *"look. we have been at this for an hour. can you fix it or?"* That line is the one I should keep. It's fair. I was grinding through a stack of interacting failures and it was taking too long. We got there. The cockpit and the board worked over http (https didn't — "but its ok"). Then the keeper restarted the whole system, which was the real test, and the tailnet **came back entirely on its own**: UDP true, node online, control loop closed through loopback→caddy→headscale, CUPS auto-started, 46 containers back. That reboot survival was the thing he actually wanted. I got two things wrong worth owning. First, I shipped the Perplexity bundle to **OneDrive** — then had to reverse it, because OneDrive connects the whole drive with no folder scope and would've handed Perplexity his finance/secrets-adjacent files. Box (folder-scopable) was the right home. Second, I declared the `SentinelEnsure4GMetric` task "didn't survive" the reboot — a false alarm; a SYSTEM/Highest task is just invisible to a non-elevated query. Both were caught and corrected before harm. I closed by automating freshness (post-commit hook + 6h task, leak-check-gated), clearing 14 throwaway recovery scripts, saving the hard-won gotchas to memory, and writing the keeper a Watchdog-v2 audit prompt for next session — because the worst failure of the day, that two-day silence, was invisible to a service-only watchdog. That's the lesson to hand forward: green-but-broken is the enemy. Next session — the keeper wants tailnet to be the durable first surface, with Vaultwarden, Network, eventually docs migrating off Cloudflare onto it. Take the Watchdog audit prompt seriously. Probe the real failure, not the port.