docs(cron): lead with agent-driven setup for no-agent mode (#19871)

The shipped no-agent docs introduced the feature via CLI first and
mentioned the chat path as a two-line afterthought. That buries the
actual value prop: the cronjob tool exposes no_agent directly to the
agent, so a user can describe a watchdog in plain language and Hermes
wires up the script + schedule + delivery without anyone opening an
editor.

Changes:

* cron-script-only.md: promote 'Create One from Chat' above
  'Create One from the CLI', flesh it out with a worked transcript
  (the actual tool calls the agent makes), add subsections covering
  'what the agent decides for you' (when to pick no_agent=True vs
  LLM mode) and 'managing watchdogs from chat' (pause/resume/edit/
  remove all agent-accessible).

* user-guide/features/cron.md:
  - Add 'no-agent mode' to the top-level feature list with a cross-
    link, plus a sentence up top making it clear everything is
    agent-accessible through the cronjob tool.
  - Add 'The agent sets these up for you' subsection to the no-agent
    section showing the exact tool call shape.

* automate-with-cron.md: tighten the existing tip box to mention the
  agent-driven path, not just CLI scheduling.

No behavior change — docs only.

website/docs/user-guide/features/cron.md

@@ -17,6 +17,9 @@ Cron jobs can:
 - attach zero, one, or multiple skills to a job
 - deliver results back to the origin chat, local files, or configured platform targets
 - run in fresh agent sessions with the normal static tool list
+- run in **no-agent mode** — a script on a schedule, its stdout delivered verbatim, zero LLM involvement (see the [no-agent mode](#no-agent-mode-script-only-jobs) section below)
+
+All of this is available to Hermes itself through the `cronjob` tool, so you can create, pause, edit, and remove jobs by asking in plain language — no CLI required.
 
 :::warning
 Cron-run sessions cannot recursively create more cron jobs. Hermes disables cron management tools inside cron executions to prevent runaway scheduling loops.
@@ -308,6 +311,24 @@ Semantics:
 
 `.sh` / `.bash` files run under `/bin/bash`; anything else under the current Python interpreter (`sys.executable`). Scripts must live in `~/.hermes/scripts/` (same sandboxing rule as the pre-run script gate).
 
+### The agent sets these up for you
+
+The `cronjob` tool's schema exposes `no_agent` to Hermes directly, so you can describe a watchdog in chat and let the agent wire it up:
+
+```text
+Ping me on Telegram if RAM is over 85%, every 5 minutes.
+```
+
+Hermes will write the check script to `~/.hermes/scripts/` via `write_file`, then call:
+
+```python
+cronjob(action="create", schedule="every 5m",
+        script="memory-watchdog.sh", no_agent=True,
+        deliver="telegram", name="memory-watchdog")
+```
+
+It picks `no_agent=True` automatically when the message content is fully determined by the script (watchdogs, threshold alerts, heartbeats). The same tool also lets the agent pause, resume, edit, and remove jobs — so the whole lifecycle is chat-driven without anyone touching the CLI.
+
 See the [Script-Only Cron Jobs guide](/docs/guides/cron-script-only) for worked examples.
 
 ## Provider recovery