Let the install set how many steps a run may take

The two limits were compiled in: a task run stopped at
AppData.HarnessMaxToolSteps (200) and a chat reply at
AppData.BotReplyMaxToolSteps (8), so an install that needed a longer task
had to rebuild.

Both are now `app_settings` rows (`harness_max_tool_steps` and
`bot_reply_max_tool_steps`), read at the two loop call sites through
grabHarnessMaxToolSteps and grabReplyMaxToolSteps, and edited by the super
admin on Settings > General beside the prompt appendix. Zero clears a
limit back to the code default, like the bot file quota.

readStepLimit keeps the saved number only when it is a whole number of at
least 1 and no more than AppData.BotStepLimitMax (1000), so a blank, a
zero or a typo falls back instead of stopping every run before its first
turn, and a huge number still ends in the wrap-up report.

runTextLoop keeps AppData.HarnessMaxToolSteps as its default, so it stays
free of database reads and its tests run as they did.

src/pages/admin/settings/general/(sections)/run-limits-section.tsx

@@ -0,0 +1,25 @@
+import { useContext } from "react";
+import { AppContext } from "@/src/pages/__root";
+import isPassThroughUser from "@/src/utils/rbac/is-pass-through-user";
+import SettingsGroup from "../../(partials)/settings-group";
+import RunLimitsForm from "../(partials)/run-limits-form";
+
+/**
+ * How long a bot may work on one task or reply before it reports. Only the
+ * super admin sees it, since it changes every bot on the install.
+ */
+export default function RunLimitsSection() {
+    const { pageProps } = useContext(AppContext);
+
+    if (!isPassThroughUser({ user_types: pageProps?.user_types })) return null;
+
+    return (
+        <SettingsGroup
+            title="Run limits"
+            description="How many turns a bot may take with its tools before it must stop and report. A task may take far more than a chat reply, since it does the long work."
+            id="run-limits"
+        >
+            <RunLimitsForm limits={pageProps?.run_limits} />
+        </SettingsGroup>
+    );
+}