feat(route): add 4pda.to forum thread route

[untitaker]

Involved Issue / 该 PR 相关 Issue

New route, no existing issue.

Example for the Proposed Route(s) / 路由地址示例

/4pda/forum/thread/669936

New RSS Route Checklist / 新 RSS 路由检查表

• New Route / 新的路由
  • Follows Script Standard / 跟随 路由规范
• Anti-bot or rate limit / 反爬/频率限制
  • If yes, do your code reflect this sign? / 如果有, 是否有对应的措施? — Sets browser-like headers (User-Agent, Accept, Accept-Language) to avoid 403 responses. Route marked with antiCrawler: true.
• Date and time / 日期和时间
  • Parsed / 可以解析 — Parses DD.MM.YY, HH:MM format
  • Correct time zone / 时区正确 — Moscow time (UTC+3)
• New package added / 添加了新的包 — Uses existing iconv-lite
• Puppeteer — Not required

Note / 说明

Adds a route to subscribe to posts in 4PDA forum threads, a popular Russian tech/mobile forum running Invision Power Board.

Features:

• Fetches the last page of a thread to get the most recent posts
• Handles windows-1251 encoding via iconv-lite (already a project dependency)
• Includes radar rules for automatic route detection from 4pda.to URLs
• Parses post author, date, floor number, and full post content
• Supports ?limit=N query parameter

Example: /4pda/forum/thread/669936 subscribes to the TP-LINK M7350 thread.

[github-actions]

Successfully generated as following:

http://localhost:1200/4pda/forum/thread/669936 - Failed ❌

HTTPError: Response code 503 (Service Unavailable)

Error Message:<br/>FetchError: [GET] &quot;https://4pda.to/forum/index.php?showtopic=669936&amp;st=0&quot;: 403 Forbidden
Route: /4pda/forum/thread/:topicId
Full Route: /4pda/forum/thread/669936
Node Version: v24.19.0
Git Hash: 7b7cc5ae

[github-actions]

Auto Review

Previous findings (hardcoded User-Agent, custom limit handling) no longer apply after the rewrite to Playwright. Remaining items on the current diff:

[AGENTS 15 - Avoid loading HTML twice]

• lib/routes/4pda/thread.ts: load(html) is called twice ($first, then $). When the thread has no pagination link, html is unchanged and the exact same markup is parsed a second time. Fix: parse once - only re-load() when a navigation actually happened (const $ = navigated ? load(await page.content()) : $first;) and reuse that object for both the pagination lookup and the post extraction.

[AGENTS 16 / 43 - Playwright resource handling]

• lib/routes/4pda/thread.ts: await destroy() is only reached on the happy path. If page.content() or the second page.goto() throws (timeout / navigation error), the browser context is never released and leaks. Fix: follow the existing convention (see lib/routes/iwara/ranking.ts:61-87) and wrap the page work in try { ... } finally { await destroy(); }.

[github-actions]

Successfully generated as following:

http://localhost:1200/4pda/forum/thread/669936 - Failed ❌

HTTPError: Response code 503 (Service Unavailable)

Error Message:<br/>Error: this route is empty, please check the original site or &lt;a href=&quot;https://github.com/DIYgod/RSSHub/issues/new/choose&quot;&gt;create an issue&lt;/a&gt;
Route: /4pda/forum/thread/:topicId
Full Route: /4pda/forum/thread/669936
Node Version: v24.19.0
Git Hash: e4982ffb

[untitaker]

I think turnstile is left as "exercise for the reader." we cannot solve it in rsshub.