fix(cluster): keep the daemons in one process instead of re-execing each pass

queue, scanner, signals and watchdog each had their whole pass inside a while
whose last statement was an unconditional break, so every pass fell out of the
loop and restartDaemon() re-executed console.php: a fresh bootstrap, settings
read and database connect per pass, per node — four times a second in the
signals daemon. The plan's 24 h RSS and queries/s acceptance cannot be measured
on a process that never lives a second.

Every break that means something (a code change, nginx stopped, MAIN's
database gone) stays, and restartDaemon() still re-execs then, which is how a
deploy is picked up. Two things fell out of it: the signals daemon paced itself
inside the branch that read `signals`, so a node whose query failed spun as
fast as MariaDB would answer; and the watchdog's CPU sample was a delta over
its own 2 s sleep every pass, because a fresh process never had a previous
read of /proc/stat.

The numeric cluster settings render as number inputs with the bounds the save
clamps to, instead of text fields that no digits-only script covered.

tests/Unit/DaemonLoopTest.php

@@ -0,0 +1,57 @@
+<?php
+
+use PHPUnit\Framework\TestCase;
+
+/**
+ * A daemon's loop must not end in an unconditional `break`.
+ *
+ * Four of them did (`queue`, `scanner`, `signals`, `watchdog`): the whole pass
+ * sat in a `while` whose last statement was `break`, so every pass fell out of
+ * the loop and `restartDaemon()` re-executed `console.php` — a fresh bootstrap,
+ * settings read and database connect per pass, per node, four times a second in
+ * the signals daemon's case. The plan's 24 h RSS and queries/s acceptance
+ * cannot be measured on a process that never lives that long.
+ *
+ * A `break` inside an `if` is how a daemon is meant to stop (a code change, an
+ * nginx restart, a dead database): only the unconditional one at the end of the
+ * body is refused.
+ */
+final class DaemonLoopTest extends TestCase {
+
+	public function testNoDaemonLoopEndsWithAnUnconditionalBreak(): void {
+		$rChecked = 0;
+
+		foreach (glob(dirname(__DIR__, 2) . '/src/Cli/Commands/*Command.php') ?: [] as $rFile) {
+			$rLines = file($rFile) ?: [];
+			if (!str_contains(implode('', $rLines), 'restartDaemon(')) {
+				continue;
+			}
+			foreach ($rLines as $rNo => $rLine) {
+				if (!preg_match('/^(\t+)(?:\} )?while \(/', $rLine, $rM)) {
+					continue;
+				}
+				$rChecked++;
+				$rEnd = self::closes($rLines, $rNo, strlen($rM[1]));
+				$rLast = $rEnd === null ? '' : trim($rLines[$rEnd - 1]);
+				$this->assertNotSame(
+					'break;',
+					$rLast,
+					basename($rFile) . ':' . $rEnd . ": the loop's last statement is an unconditional break, so the daemon re-executes itself every pass"
+				);
+			}
+		}
+
+		$this->assertGreaterThan(4, $rChecked, 'the daemon loops were not found at all');
+	}
+
+	/** The line (0-based) of the `}` that closes a block opened at $rNo, indented with $rTabs tabs. */
+	private static function closes(array $rLines, int $rNo, int $rTabs): ?int {
+		$rClose = str_repeat("\t", $rTabs) . '}';
+		for ($i = $rNo + 1; $i < count($rLines); $i++) {
+			if (str_starts_with($rLines[$i], $rClose)) {
+				return $i;
+			}
+		}
+		return null;
+	}
+}