Code Farm: per-plot auto-replant pause and crop-lock check; community sync and node work

Continuous Delivery could never be turned off once a crop was planted. Add a
one-shot per-plot "stop after harvest" flag (POST /game/plot/stop, Devii tool
game_plot_stop, game_plots.stop_after_harvest), cleared by the next plant,
autoreplant claim or Refactor. Autoreplant now also respects crop locks through
the shared _crop_lock predicate. Plan and measurements in happyplanting.md.

Also includes the pending community sync, node network and related work in the
tree; the full suite passed (4999) with all of it.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

nodes/client/battery_darwin.go

@@ -0,0 +1,19 @@
+//go:build darwin
+
+package main
+
+import (
+	"context"
+	"os/exec"
+	"time"
+)
+
+func systemBattery() (bool, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+	defer cancel()
+	out, err := exec.CommandContext(ctx, "pmset", "-g", "batt").Output()
+	if err != nil {
+		return false, err
+	}
+	return parsePmset(string(out)), nil
+}