fix(ui): add existence check for session in updateConfirmingWorktreeRemoval

[dnlopes]

Summary

The updateConfirmingWorktreeRemoval method in model.go accesses m.sessionState.Sessions[session.Name] without checking if the key exists, unlike other handlers (handleKillSession, handleArchiveSession) which use getFreshSessionInfo().

Problem

Location: internal/ui/model.go:743

When a user initiates a "kill session" action on a session with a worktree:

1. handleKillSession uses getFreshSessionInfo() to check if session exists and has worktree
2. If yes, it opens a confirmation dialog asking "Remove worktree too?"
3. User makes a choice → updateConfirmingWorktreeRemoval handles the response

The gap is in step 3. Between steps 1 and 3, time passes while the user reads and interacts with the dialog. During this time, another process or user could delete the session.

Current code:

sessionInfo := m.sessionState.Sessions[session.Name]
worktreePath := sessionInfo.WorktreePath
repoPath := sessionInfo.RepoPath

If the session was deleted:

• sessionInfo becomes a zero-value domain.Session{}
• worktreePath and repoPath become empty strings
• The code continues silently, potentially calling RemoveWorktree("", "") with unexpected behavior

Contrast with handleKillSession (line 580):

if sessionInfo, ok := m.getFreshSessionInfo(sessionName); ok && sessionInfo.WorktreePath != "" {
    // Safe: we know session exists
}

Why It Matters

• Silent failures are hard to debug
• Operating on stale/missing data can lead to confusing error messages
• Inconsistent patterns make code harder to maintain

Proposed Solution

Add existence check before accessing session info:

sessionInfo, ok := m.sessionState.Sessions[session.Name]
if !ok {
    logging.Logger.Warn("Session no longer exists during worktree removal", "session", session.Name)
    m.state = stateList
    m.worktreeRemovalForm = nil
    m.sessionToKill = nil
    m.formRemoveWorktree = nil
    return m, m.sessionList.Init()
}

Related Code

• handleKillSession (line 580) - correctly uses getFreshSessionInfo
• handleArchiveSession (line 596) - correctly uses getFreshSessionInfo
• getFreshSessionInfo helper (line 564) - loads fresh state and checks existence

Labels

• bug
• good first issue