feat: termora-cli — a CLI for AI agents to reuse saved SSH hosts

[ruanun]

Summary

Adds termora-cli, a command-line entry (shipped via jpackage --add-launcher) that lets external AI agents — Claude Code, Codex, etc. — reuse the SSH hosts already saved in Termora to run one-off commands and transfer files, without ever exposing credentials. Paired with a bundled SKILL.md, an agent can drive it directly.

Features

• Commands: assets list / exec / upload / download; JSON output when piped, human-readable in a TTY
• exec opens a temporary SSH connection (reuses core SshClients, incl. jump hosts) and returns clean stdout/stderr/exit code
• Defense-in-depth, opt-in (default off): master switch + host whitelist (empty by default) + dangerous-command guard + audit log
• Settings → "Command Line": enable switch, tree-grouped host whitelist (non-SSH hosts greyed out), copy / install the Skill to Claude & Codex, add termora-cli to PATH
• Bundled SKILL.md (a format shared by Claude Code and Codex)

Design

• Standalone launcher talking to core directly (the DB is self-unlocking, so no running GUI is required); no MCP/HTTP layer — kept minimal.
• Built-in, not an external plugin: the CLI depends deeply on core SSH/credential handling and the launcher is a build artifact, so it can't be a loadable plugin; optionality is expressed via the default-off master switch.

Changes

• New app.termora.cli.** (CLI core) and app.termora.plugin.internal.cli.** (settings UI)
• Core: register an internal plugin in PluginManager; widen ApplicationInitializr.setupNativeLibraries to internal for CLI reuse; build.gradle.kts adds --add-launcher + --enable-native-access and tightens the pty4j native-extraction glob
• i18n for all 6 languages; adds SKILL.md

Testing

• 33 unit tests + 8 integration tests (Testcontainers real sshd)
• Verified end-to-end on Windows: full jpackage build, real-host exec/upload/download (incl. a jump host), master-switch default-off, native warnings suppressed

Notes for reviewers

• The CLI reuses SshClients from the *.internal.ssh package (public API, "internal" package) — mirrors the existing headless SFTP path; happy to promote it to a dedicated public API if preferred.
• Cross-platform packaging (macOS/Linux add-launcher, PathInstaller symlink, pty4j extraction) is code-reviewed and reasoned correct but only build-tested on Windows — CI on the other platforms would be the final confirmation.