Add limited auto track option

[kondi]

Summary

Introduce an optional setting to automatically enable tracking when saving a session for the current window only, under controlled conditions. The implementation is backward-compatible, and the new configuration option is disabled by default.

Related: #1532 (refined to apply only to current-window saves with strict scoping)

Motivation

In my workflow, when I save the current window, I want to start tracking it immediately.

Today, that requires the following steps:

1. Save the current window as a new session
2. Enable tracking for that session
3. Open the created session in a new window
4. Close the original window

These steps add unnecessary friction to a workflow that is otherwise naturally window-scoped.

This feature is intended to streamline that workflow while preserving the existing session-based design and avoiding ambiguity.

Proposed Behavior

Add a new setting:

• Automatically track saved current window sessions

When enabled:

• if the user saves a session using "Save only current window"
• and there is no active tracking session already associated with that window (to avoid conflicts)

then the newly created session is automatically marked as a tracking session and begins tracking the existing current window immediately.

Explicit Non-Goals

To avoid ambiguity and unintended side effects, this feature:

• does not apply when saving all windows
• does not override or replace an existing tracking session for the same window
• does not affect other windows implicitly
• does not enable global or multi-window tracking

Expected Benefits

• Reduces friction for users working in window-scoped workflows
• Improves ergonomics for users who regularly save and track the current window
• Preserves the current explicit tracking model while offering an optional convenience feature

Design Considerations

• Tracking remains opt-in through a dedicated setting
• Behavior is strictly scoped to reduce ambiguity
• Existing session and tracking semantics remain unchanged
• Default behavior is unchanged