Add two-stage run verification and 24-hour Activity filter

Status now reads "Sent" when the confirmation click lands, since that
only means MassPrice accepted the run request, not that it finished —
their own processing is async and takes anywhere from ~1 to ~22
minutes in observed practice. A new "Complete" column tracks that
separately: run_rule() captures a watermark (the target rule's current
top data-activitylogid on /Activity/List, not the displayed timestamp
string, to sidestep fragile date/timezone parsing) before submitting,
and scheduler.py schedules a one-off verify_run() job
VERIFY_DELAY_MINUTES later to check whether a new "Complete" entry
appeared past that watermark.

rebuild_jobs() now only clears recurring "rule-*" jobs, not the one-off
"verify-*" jobs, so editing a schedule can't cancel a verification
that's already in flight for an earlier run.

Also scopes the Activity page to the last 24 hours per request.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01H6TgffxTvYhqxykAbVQg2v

.env.example

@@ -18,6 +18,14 @@ HOST_PORT=5057
 # Controls what "6:00 AM" means for your schedules
 TZ=America/Phoenix
 
+# ── Run verification delay ──────────────────────────────────────────
+# Minutes to wait after a run is confirmed sent before checking
+# MassPrice's own Activity Log to see whether it actually completed.
+# MassPrice's processing time varies a lot in practice (observed
+# anywhere from ~1 to ~22 minutes) — this is a reasonable middle
+# ground, not a guarantee.
+VERIFY_DELAY_MINUTES=10
+
 # ── Session-expiry email alert (optional) ───────────────────────────
 # Sent once when the saved MassPrice session expires/is missing — not
 # on every failed run, just the first one after it goes bad. Same