feat: add daily note target database setting

[eloklam]

Summary (EN)

Adds an optional per-notebook setting dailyNoteDatabaseID: when a NEW daily note is created for that notebook, the newly created daily note document is automatically added as a row to the configured target database (Attribute View). Existing daily notes are never re-added (idempotent), and an empty setting keeps the current behaviour unchanged. The notebook settings dialog gains a block picker so the target database is chosen from the list of existing databases rather than typed manually.

Summary (zh-CN)

新增可选的笔记本级设置 dailyNoteDatabaseID：当该笔记本创建新的日记时，自动将新建的日记文档作为一行添加到配置的目标数据库（属性视图）中。已存在的日记不会被重复添加（幂等），设置为空时保持原有行为不变。笔记本设置对话框新增块选择器，可从已有数据库列表中选择目标数据库，无需手动输入 ID。

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Changes (EN)

• kernel/conf/box.go: add DailyNoteDatabaseID field to BoxConf (persisted in the notebook's .siyuan/conf.json), default empty.
• kernel/model/file.go: in CreateDailyNote, after a new daily note doc is created, if DailyNoteDatabaseID is set, resolve the AV id from the stored database block id and add the doc as a row via AddAttributeViewBlock. Best-effort: any failure only logs a warning and never fails daily note creation. Idempotent (only the newly-created branch runs, plus a bound-item pre-check).
• kernel/model/import.go: preserve DailyNoteDatabaseID when importing notebook conf from .sy.zip.
• kernel/api/notebook.go: setNotebookConf accepts and trims the new field (empty allowed, permissive validation).
• app/src/menus/onGetnotebookconf.ts: extend the notebook settings dialog with a "Target database (Attribute View)" row: shows the currently selected database name/path (or block id) and a "Select database…" button opening a picker listing all databases (/api/av/searchAttributeView), including a "Clear" entry to disable.
• app/appearance/langs/{en,zh-CN,zh-TW}.json: add dailyNoteDatabaseId, dailyNoteDatabaseIdHint, dailyNoteDatabasePick strings.
• scripts/dailynote-database-smoke.mjs: smoke test covering row insertion, idempotency, and unset-setting behaviour.

Changes (zh-CN)

• kernel/conf/box.go：BoxConf 新增 DailyNoteDatabaseID 字段（持久化到笔记本 .siyuan/conf.json），默认空。
• kernel/model/file.go：CreateDailyNote 创建新日记后，若配置了 DailyNoteDatabaseID，从数据库块 ID 解析 AV id 并通过 AddAttributeViewBlock 将文档作为行加入。尽力而为：任何失败仅记录警告，不影响日记创建。幂等（仅在新建分支执行，并有已绑定预检查）。
• kernel/model/import.go：从 .sy.zip 导入笔记本配置时保留 DailyNoteDatabaseID。
• kernel/api/notebook.go：setNotebookConf 接受并去除该字段首尾空白（允许为空，宽松校验）。
• app/src/menus/onGetnotebookconf.ts：笔记本设置对话框新增「目标数据库（属性视图）」行：显示当前所选数据库名称/路径（或块 ID），并提供「选择数据库…」按钮打开选择器，列出所有数据库（/api/av/searchAttributeView），含「清空」项可禁用。
• app/appearance/langs/{en,zh-CN,zh-TW}.json：新增 dailyNoteDatabaseId、dailyNoteDatabaseIdHint、dailyNoteDatabasePick 文案。
• scripts/dailynote-database-smoke.mjs：覆盖行插入、幂等性、未设置行为的冒烟测试。

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How it was verified (EN)

• Kernel: CGO_ENABLED=1 go build -tags "fts5 sqlcipher" -o /tmp/siyuan-dbadd-kernel/SiYuan-Kernel . — success.
• Frontend: cd app && corepack pnpm run build:desktop — webpack compiled successfully (only pre-existing size warnings).
• Smoke (node scripts/dailynote-database-smoke.mjs, isolated temp workspace, fresh port, lang zh-TW):
  1. initial AV rowCount = 0
  2. setNotebookConf persists dailyNoteDatabaseID
  3. 1st createDailyNote → exactly 1 row, bound to the new note doc
  4. 2nd createDailyNote (same day) → same doc, still 1 row, same itemID (idempotent)
  5. notebook without the setting → daily note created normally
  • Result: SMOKE_TEST_OK: dailyNoteDatabaseID feature verified

How it was verified (zh-CN)

• 内核：CGO_ENABLED=1 go build -tags "fts5 sqlcipher" -o /tmp/siyuan-dbadd-kernel/SiYuan-Kernel . — 成功。
• 前端：cd app && corepack pnpm run build:desktop — webpack 编译成功（仅原有体积警告）。
• 冒烟测试（node scripts/dailynote-database-smoke.mjs，隔离临时工作空间、独立端口、zh-TW）：初始 0 行 → 设置持久化 → 首次创建日记恰好 1 行且绑定新文档 → 同日再次创建仍 1 行且 itemID 不变（幂等）→ 未设置时行为不变。结果：SMOKE_TEST_OK。