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/schemas/harness-schema.ts

@@ -1,4 +1,5 @@
 import { z } from "zod";
+import { AppData } from "@/src/data/app-data";
 import { Harnesses, type HarnessKind } from "@/src/dict/harness-dict";
 import {
     HarnessProviderKinds,
@@ -96,6 +97,17 @@ export type SaveBotHarnessSettingsRequest = z.infer<
     typeof SaveBotHarnessSettingsRequestSchema
 >;
 
+/**
+ * The General settings' run limits: model turns a task run and a chat reply
+ * may take. Zero puts the code's default back.
+ */
+export const SaveRunLimitsRequestSchema = z.object({
+    task_steps: z.coerce.number().int().min(0).max(AppData.BotStepLimitMax),
+    reply_steps: z.coerce.number().int().min(0).max(AppData.BotStepLimitMax),
+});
+
+export type SaveRunLimitsRequest = z.infer<typeof SaveRunLimitsRequestSchema>;
+
 export const PreviewVoiceRequestSchema = z.object({
     model_id: z.coerce.number().int().positive("Pick a speech model"),
     voice: z.string().trim().max(200).optional(),