fix(dag): sweep freeze window covers the live watcher's actual cadence

[LeXwDeX]

Closes#342

What

The sweep's freeze window derived solely from the current persisted config cadence. Replan can lower a running node's timeout_ms while the A1/Q2 re-time gate deliberately keeps the old watcher on its old (longer) cadence — a config-only window is then shorter than the live watcher's cycle and sweeps a healthy node mid-decision-window.

Fix: window = max(config cadence, escalateIntervalDurable(deadline_ms, started_at)).

deadline_ms is only ever written as grant time + timeout_ms — at spawn and at each deadline extension (escalations move only the counter, never the deadline; verified in projector.tsNodeTimeoutEscalated vs NodeDeadlineExtended folds). So (deadline − started_at) — the sum of the initial grant plus every extension grant — is always ≥ the last grant, and the last grant's timeout IS the live watcher's cadence. The bound over-estimates after extensions (delays detection, never causes a premature settle); missing columns (legacy rows) return 0 so the config decides alone.

Tests

• Pure: durable-bound derivation (spawn-only, escalations-don't-move-deadline, extension over-estimate, 1s floor, legacy fallbacks)
• Pure: the fix(dag): supervision sweep freeze-window uses current config cadence — replan timeout reduction can prematurely kill live nodes #342 incident math — config lowered 30min→10min with a live 30min watcher keeps the 31-tick window (was 11); re-timed watcher keeps 11
• bun run typecheck green; new pure tests 2/2

Note: the 3 wall-clock-sensitive integration cases in this file fail on this loaded local machine at f25f37d7e too (pre-date this change); CI is the arbiter.