[FEATURE]: Add --all flag to /sessions command to view sessions across all projects #17842

Feature hasn't been suggested before.

• I have verified this feature I'm about to request hasn't been suggested before.

Describe the enhancement you want to request

Problem

The /sessions command only shows sessions from the current working directory. This makes it impossible to find or resume sessions from other projects without navigating to each project directory individually.

Current Behavior

• Sessions are stored globally in ~/.local/share/opencode/storage/session/global/
• But /sessions filters by current directory, showing only sessions created in that specific path
• Users with multiple projects cannot see their full session history from one location

Example

I have 16 sessions stored across different directories:

• 7 from C:\Prodprog
• 3 from C:\Prog\program1
• 3 from C:\Prog\program2\pog
• 2 from C:\Users\someuser When running /sessionsfromC:\Prog\program3I only see 2 sessions (the ones created in that directory). My other 14 sessions are effectively invisible unless Icd to each original directory.

Proposed Solution

Add an --all or -a flag to the /sessions command:
/sessions --all # Show sessions from ALL projects
/sessions -a # Short form

Optional Enhancements

• Group results by project directory for readability
• Add a --project <path> flag to filter to a specific project without navigating there
• Show project path in the session list output

Use Cases

1. Session recovery: Finding an old session when you don't remember which project it was in
2. Cross-project context: Quickly referencing work done in related projects
3. Session cleanup: Viewing all sessions to identify ones to delete
4. Workflow continuity: Resuming work when switching between multiple projects

Environment

• OS: Windows 10 (Git Bash)
• opencode version: 1.2.x
• Session storage: ~/.local/share/opencode/storage/session/global/