feat: SQL 库与终端 reintegrate 恢复（#313） - #383

Closes #313

Description

本 PR 包含两个特性：

1. SQL 库（standalone SQL library）

Adds a standalone SQL library: a global, connection-agnostic home for .sql
documents, so scripts no longer have to live inside a per-(connection+database)
query folder.

• core: new storage::sql_library module — default library root
  (<data_dir>/sql-library, deliberately outside ~/Documents to avoid the
  macOS TCC prompt), mounted user directories persisted to
  config/sql-library-directories.json, directory listing, create / rename /
  delete for .sql files and subfolders, and shared SQL file-name validation.
• db_view: new SqlLibraryPanel, reachable from a rail button on the database
  tab's right sidebar. Lazy-loading tree (one level per expand), create / rename /
  delete / remove-from-library dialogs, notifications, empty and load-error
  placeholders.
• Clicking a .sql file opens it in the existing SQL editor, reusing syntax
  highlighting, execution and autosave. Tabs are keyed by file path, so clicking
  the same file again focuses the tab that is already open.
• Library files are not bound to a connection: the current tree selection (or the
  first connection) is used as the default, and the connection can be switched
  inside the editor. If no connection exists, the panel just notifies instead of
  opening an empty editor.
• File-name validation moved to core::storage::sql_library
  (sql_file_path_for_name); db_view::sql_editor_view::query_file_path_for_name
  now delegates to it, removing the duplicated implementation.
• Removing a mounted directory only detaches it from the library, the files stay
  on disk.

2. 终端 reintegrate 恢复（terminal.control action=reintegrate）

嵌套 shell（sudo -i / su）不继承运行时注入的 shell integration，OSC 133
事件流断开后 supervisor readiness 卡死在瞬态，terminal.exec 持续
terminal_busy 且 interrupt 的 ETX 无法恢复（空提示符上只回显 ^C，
不产生 OSC 事件）。

• ExecSupervisor::reintegrate_shell 门控：exec 在途 / 断连拒绝，卡在
  SubmissionPending / CommandRunning 瞬态时放行，不改状态
• SSH actor 写 runtime_shell_integration_command() 重注入；新提示符的
  OSC InputStart 无条件翻回 Ready，状态机自愈，等 1-2 秒重试 exec 即可
• local actor 返回 terminal_control_unsupported（本地集成形态不同，fail
  closed）
• readiness_before 改 Option，reintegrate 恒 None
• Busy 出口富化为 BusyContext{readiness}，指引 Agent 走
  read → reintegrate → retry 自救链路
• Agent 自救链：exec busy（带 readiness 快照）→ terminal.read 确认空闲
  提示符 → control action=reintegrate → 重试

Screenshot

No screenshots attached — the UI has not been captured yet.

How to Test

Automated, run on top of origin/main (this branch's base):

SQL 库:

• cargo test -p one-core sql_library → 13 passed, 798 filtered out
• cargo test -p db_view sql_library → 11 passed, 914 filtered out
• cargo check -p main → 0 errors

The db_view suite covers the tree state machine (expansion, lazy loading, stale
state on root reset) and source-level contracts for the wiring and the i18n keys;
the core suite covers the storage layer against a temp directory, never the real
config dir.

reintegrate:

• cargo test -p terminal --lib reintegrate → 10 passed（门控 fail-closed、
  瞬态放行、端到端自愈、SSH actor 注入 contract、local Unsupported contract）
• cargo test -p public_mcp --test terminal_control → schema enum、parse、
  reintegrate 结果 readiness_before=null、未知 action 拒绝
• cargo test -p terminal -p public_mcp -p terminal_view → 1307 passed, 0 failed
• cargo clippy -p terminal -p public_mcp -p terminal_view --all-targets →
  新增代码零告警
• cargo check -p main → 0 errors

Manual: SSH 连接后进入 sudo -i，确认 terminal.exec 报带指引的 busy，
terminal.read 看到空闲 root 提示符后 terminal.control action=reintegrate，
1-2 秒后重试 exec 正常执行。