nudges: a resolved outcome and a way to close a pending alarm (V-535)

The sev4 repeat path reads the nudges table, so ending an alarm means
writing an ending there. 'resolved' is the daemon closing it because the
condition cleared, which is neither 'acted' nor 'ignored'.

ResolvePendingTelegram is rule-scoped and accepts only the two endings the
daemon may write. OldestPendingTelegram backs the age cap and scans into a
NullInt64, because MIN over an empty set is one NULL row, not zero rows.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

internal/store/schema.sql

@@ -43,7 +43,9 @@ CREATE TABLE IF NOT EXISTS nudges (
   rule        TEXT    NOT NULL,
   channel     TEXT    NOT NULL,
   message     TEXT    NOT NULL,
-  outcome     TEXT    NOT NULL DEFAULT 'pending' CHECK (outcome IN ('pending','acted','snoozed','ignored')),
+  -- 'resolved' is the daemon closing an alarm because the condition cleared,
+  -- as opposed to 'acted' (he answered) or 'ignored' (nobody ever did).
+  outcome     TEXT    NOT NULL DEFAULT 'pending' CHECK (outcome IN ('pending','acted','snoozed','ignored','resolved')),
   outcome_ts  INTEGER
 );
 CREATE INDEX IF NOT EXISTS idx_nudges_rule_ts ON nudges (rule, ts DESC);