fix(tabs): route hotkey duplicate through the tab menu duplicate path - #483

Description

This PR fixes tab duplication so a duplicated tab preserves the working directory and connection settings of the source tab.

Previously the hotkey duplicated the active tab through its own HomePage::duplicate_active_tab path, which reopened tabs by connection kind and had several problems:

• Local terminals fell back to default settings, losing the CWD and any custom/WSL profile.
• SSH terminals ignored the current directory.
• Temporary connections silently did nothing when no StoredConnection matched.
• The copy never subscribed to the terminal's OpenSftp / SaveAsConnection events.

Now duplication delegates to TabContainer::duplicate_active_tab (the same path the tab context menu uses) and emits TabContainerEvent::TabDuplicated, so HomePage can attach the terminal event subscriptions to the copy. The inherited _ONETCLI_SHELL_INTEGRATED is also cleared for new sessions: a host process launched from a Navop terminal carries this variable, the integration script's re-entry guard returns early, OSC 7 stops being reported, and duplicated tabs lose the CWD.

In addition, two shell-integration tests are made parallel-safe by isolating them in their own tempfile::tempdir() directories instead of sharing the process-level $TMPDIR/onetcli-<pid> (which made one test delete the other's files).

How to Test

1. Open a Navop terminal and cd into a project directory.
2. Press the duplicate-tab hotkey (or use the tab context menu "Duplicate").
3. Confirm the duplicated tab opens in the same directory with the same connection settings (local custom/WSL profile, SSH remote, etc.).
4. From a Navop terminal, launch a child process that starts a new terminal and duplicate it again; confirm the CWD is still preserved (no lost OSC 7 reporting).
5. Run the affected tests:

   cargo test -p terminal prepare_shell_integration
   cargo test -p one_core tab_container
   cargo run
   

Checklist

• I have read the CONTRIBUTING document and followed the guidelines.
• Reviewed the changes in this PR and confirmed AI generated code (If any) is accurate.
• Passed cargo run for story tests related to the changes.
• Tested macOS, Windows and Linux platforms performance (if the change is platform-specific)