feat(biz): add wx biz-articles command to query public account messages

[ChenyqThu]

feat(biz): add wx biz-articles command to query public account messages

Summary

Adds a new biz-articles subcommand that queries locally cached WeChat public account (公众号) article pushes from biz_message_0.db.

This enables a downstream workflow for downloading full article content:

wx biz-articles --since today --json | jq '.[].url' | xargs opencli weixin download

Background

• WeChat stores public account (官方账号) message pushes in a separate database: message/biz_message_0.db (SQLCipher 4 encrypted)
• This DB was not exposed by any existing wx-cli command
• The encryption key is already scanned and stored in ~/.wx-cli/all_keys.json by wx init
• Each public account has its own Msg_{md5(username)} table, following the same convention as message_0.db
• Message content is zstd-compressed XML containing <mmreader>/<item> structures with article metadata

New CLI Interface

# Last 50 articles (default)
wx biz-articles

# More articles
wx biz-articles -n 200

# Filter by public account name (fuzzy match on display name)
wx biz-articles --account "返朴"
wx biz-articles --account "Datawhale"

# Time filter (article publish time, YYYY-MM-DD)
wx biz-articles --since 2026-05-10
wx biz-articles --since 2026-05-01 --until 2026-05-10

# Show only accounts with unread messages, one latest article per account
wx biz-articles --unread
wx biz-articles --unread --account "Datawhale"   # combine: unread within specific account

# JSON output (for downstream piping)
wx biz-articles --json
wx biz-articles --since 2026-05-10 --json | jq '.[].url'

Output Fields

Each article item includes:

Field	Description
time	Article publish time (formatted)
timestamp	Article publish timestamp (seconds)
recv_time	Message receive time (when WeChat pushed it)
recv_time_str	Message receive time (formatted)
account	Public account display name
account_username	Public account username (gh_*)
title	Article title
url	Article URL (mp.weixin.qq.com link)
digest	Article summary/excerpt
cover_url	Cover image URL

Implementation Notes

• biz_message_0.db is loaded on-demand via existing DbCache mechanism (no startup cost unless biz-articles is called)
• The key for message/biz_message_0.db is already in all_keys.json, no changes to wx init needed
• Multi-article pushes (图文消息) are expanded: each <item> in <mmreader> becomes a separate output row
• Items without URL or title (e.g., payment notifications from service accounts) are filtered out
• New extract_cdata helper function strips CDATA wrappers from XML content
• Results sorted by pub_time DESC (article publish time, not message receive time)

--unread semantics

• Queries session.db for unread_count > 0 rows whose chat_type == official_account, intersects with --account filter if both provided
• Returns at most one latest article per account (dedupe by account_username after the global pub_time DESC sort)
• Aligns with the behavior of wx unread --filter official for fast "what unread accounts are there + what's the latest title" scanning
• Empty intersection short-circuits before scanning biz tables

Changes

• src/ipc.rs: Add BizArticles IPC request variant
• src/cli/biz_articles.rs: New CLI command handler (follows sns_feed pattern)
• src/cli/mod.rs: Register BizArticles subcommand in clap + dispatch
• src/daemon/query.rs: Add q_biz_articles query + parse_biz_xml_items + extract_cdata helpers + 8 unit tests
• src/daemon/server.rs: Add dispatch case for BizArticles

Test Results

test result: ok. 49 passed; 0 failed; 0 ignored

New tests (8):

• biz_tests::extract_cdata_normal
• biz_tests::extract_cdata_empty
• biz_tests::extract_cdata_url
• biz_tests::extract_cdata_no_cdata_wrapper
• biz_tests::parse_biz_xml_items_single_article
• biz_tests::parse_biz_xml_items_skips_no_url
• biz_tests::parse_biz_xml_items_multi_article
• biz_tests::parse_biz_xml_items_pub_time_fallback

Verified Output (real WeChat install with ~30 public accounts, 2026-05-10)

- account: <Account A>
  title: <Sample tech article title>
  url: http://mp.weixin.qq.com/s?__biz=<redacted>&mid=<id>&idx=1&sn=<hash>
  digest: <Article excerpt>
  cover_url: https://mmbiz.qpic.cn/<redacted>
  time: 2026-05-10 17:01
  recv_time_str: 2026-05-10 17:06

- account: <Account B>
  title: <Another article>
  url: http://mp.weixin.qq.com/s?__biz=<redacted>&mid=<id>&idx=1&sn=<hash>