docs: consolidate DoS docs into security-model pages

Merge DoS guidance into security-model docs in both English and Chinese, and remove the placeholder dos.md pages to avoid duplicate/redirect-only docs.

Co-authored-by: Cursor <[email protected]>

docs/source/tutorials/dos.md

@@ -1,60 +0,0 @@
----
-title: DoS Prevention
----
-
-When the template or data context cannot be trusted, enabling DoS prevention options is crucial. LiquidJS provides 3 options for this purpose: `parseLimit`, `renderLimit`, and `memoryLimit`.
-
-## TL;DR
-
-Setting these options can largely ensure that your LiquidJS instance won't hang for extended periods or consume excessive memory. These limits are based on the available JavaScript APIs, so they are not precise hard limits but thresholds to help prevent your process from failing or hanging.
-
-For the security boundary and production hardening guidance, see [Security Model][security-model].
-
-```typescript
-const liquid = new Liquid({
-    parseLimit: 1e8, // typical size of your templates in each render
-    renderLimit: 1000, // limit each render to be completed in 1s
-    memoryLimit: 1e9, // memory available for LiquidJS (1e9 for 1GB)
-})
-```
-
-When a `parse()` or `render()` cannot be completed within given resource, it throws.
-
-## parseLimit
-
-[parseLimit][parseLimit] restricts the size (character length) of templates parsed in each `.parse()` call, including referenced partials and layouts. Since LiquidJS parses template strings in near O(n) time, limiting total template length is usually sufficient.
-
-A typical PC handles `1e8` (100M) characters without issues.
-
-## renderLimit
-
-Restricting template size alone is insufficient because dynamic loops with large counts can occur in render time. [renderLimit][renderLimit] mitigates this by limiting the time consumed by each `render()` call.
-
-```liquid
-{%- for i in (1..10000000) -%}
-    order: {{i}}
-{%- endfor -%}
-```
-
-Render time is checked on a per-template basis (before rendering each template). In the above example, there are 2 templates in the loop: `order: ` and `{{i}}`, render time will be checked 10000000x2 times.
-
-For time-consuming tags and filters within a single template, the process can still hang. For fully controlled rendering, consider using a process manager like [paralleljs][paralleljs].
-
-## memoryLimit
-
-Even with small number of templates and iterations, memory usage can grow exponentially. In the following example, memory doubles with each iteration:
-
-```liquid
-{% assign array = "1,2,3" | split: "," %}
-{% for i in (1..32) %}
-    {% assign array = array | concat: array %}
-{% endfor %}
-```
-
-[memoryLimit][memoryLimit] restricts memory-sensitive filters to prevent excessive memory allocation. As [JavaScript uses GC to manage memory](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Memory_management), `memoryLimit` limits only the total number of objects allocated by memory sensitive filters in LiquidJS thus may not reflect the actual memory footprint.
-
-[paralleljs]: https://www.npmjs.com/package/paralleljs
-[parseLimit]: /api/interfaces/LiquidOptions.html#parseLimit
-[renderLimit]: /api/interfaces/LiquidOptions.html#renderLimit
-[memoryLimit]: /api/interfaces/LiquidOptions.html#memoryLimit
-[security-model]: /tutorials/security-model.html

docs/source/tutorials/security-model.md

@@ -28,3 +28,18 @@ If you run an online service, avoid rendering fully user-defined templates whene
 - Prefer curated templates or a restricted template subset.
 - If user-defined templates are required, isolate rendering (worker/process/container), enforce OS/container memory and CPU limits, and apply request rate limits.
 - Treat `parseLimit`/`renderLimit`/`memoryLimit` as one layer in a broader DoS defense strategy.
+
+## DoS limits quick reference
+
+LiquidJS provides 3 DoS-oriented options:
+
+- [parseLimit][parseLimit]: limit total template size per `parse()` call.
+- [renderLimit][renderLimit]: limit total render time per `render()` call.
+- [memoryLimit][memoryLimit]: cooperatively limit memory-sensitive allocations counted by LiquidJS.
+
+For heavy single-template operations, process-level isolation is still recommended (for example with [paralleljs][paralleljs]).
+
+[paralleljs]: https://www.npmjs.com/package/paralleljs
+[parseLimit]: /api/interfaces/LiquidOptions.html#parseLimit
+[renderLimit]: /api/interfaces/LiquidOptions.html#renderLimit
+[memoryLimit]: /api/interfaces/LiquidOptions.html#memoryLimit