hub v0.63.0 — system-initiated immediacy: wire poke/bump at every mutation site that lacked one

The immediate-sync arc covered only operator-initiated desired-state changes;
system-initiated mutations bumped the generation silently, so a freshly onboarded
box waited a full agent tick for state the hub had already minted (observed live at
slice-C onboarding). Wire the existing, live-proven notifiers into every system site
on the correct plane — call-site wiring only, no new mechanism.

Agent plane (poke.Notifier):
- web/pbsdr.go: PBSDRAutoProvision (the observed lag), ReissuePBSDR (also lifts the
  pbsdrheal reconciler escalation, zero reconciler changes), handlePBSDRReissue —
  each pokes AFTER the successful SetHostDesired, never on a blocked/error path.
- api: new nil-safe Poker seam (PokeHost/PokeAllHosts + SetPoker); handleAdminSetDesiredState
  pokes the target host; handleAdminSetOperatorPeer fires PokeAllHosts only when the
  fleet generation bump succeeded (fire-after-commit).
- main.go: one poke.Notifier now feeds both planes (SetPoke + SetPoker).

Controller plane (intent.Hub.Bump):
- api/reissueOnReenroll: one nil-guarded bump so a long-polling controller wakes in
  seconds instead of on the 15-min cycle.

Deliberate non-sites (unchanged): WG register (undeliverable pre-tunnel — the agent
fast-tick SECONDARY owns it), WG delete (transport removed), pbsdrheal Restage (no
generation bump → the 60s ticker is the pickup path). internal/pbsdrheal byte-unchanged.

Tests: 10 non-hollow tests (web async channel-synchronized fake sender; api synchronous
fake Poker) with explicit zero-count negatives; representative red-proofs per group
(A/B/C/D) run-fail-restored. Green: go build/vet/test all pass.

hub/internal/api/wg.go

@@ -504,6 +504,8 @@ func (h *Handler) handleAdminSetOperatorPeer(w http.ResponseWriter, r *http.Requ
 	bumped, berr := h.store.BumpAllHostGenerations()
 	if berr != nil {
 		h.logger.Printf("[WARN] operator peer set but generation bump failed: %v", berr)
+	} else if h.poker != nil {
+		h.poker.PokeAllHosts() // agent-plane immediate-sync (Direction-2a): every host generation moved → fleet nudge (fire-after-commit)
 	}
 	h.logger.Printf("[INFO] operator OOB peer set: %s -> %s/32 (sync=%s, %d host generations bumped)",
 		req.Pubkey, req.AssignedIP, syncStatus, bumped)