fix: use ctrl modifier for session browser shortcuts to avoid search conflict

[dgageot]

Plain s, f, and c keys were intercepted by the star, filter, and copy-id actions before reaching the search text input, making it impossible to search for sessions containing those characters.

Change the key bindings to ctrl+s, ctrl+f, and ctrl+c so that unmodified key presses are forwarded to the search input as expected.

Fixes #1642

Follow up of #1653

[github-actions]

Review Summary

⚠️ Critical Issue Found: The PR introduces ctrl+c as a key binding for copying session IDs, but this conflicts with the global quit handler and will never work as intended.

Problem

The session browser dialog binds ctrl+c to copy session IDs (lines 45, 309), but HandleQuit() is called before the dialog's key bindings are processed (line 61 in Update()). This means:

• When users press ctrl+c, the app immediately quits via HandleQuit()
• The CopyID handler is never reached
• Users cannot copy session IDs using the advertised shortcut

Evidence

In session_browser.go Update method:

case tea.KeyPressMsg:
    if cmd := HandleQuit(msg); cmd != nil {
        return d, cmd  // ← Returns here for ctrl+c
    }
    // ... later code never reached
    case key.Matches(msg, d.keyMap.CopyID):  // ← Unreachable for ctrl+c

Recommendation

Choose a different key binding for CopyID that doesn't conflict with the global quit handler. Consider:

• ctrl+y (yank/copy in some editors)
• ctrl+alt+c (less common, unlikely to conflict)
• alt+c (modifier but not ctrl)

The original issue #1642 was about conflicts with search input (s, f, c). Using ctrl+s and ctrl+f solves that, but ctrl+c creates a different conflict.

fixed