feat: add edit multi-repo paths dialog (p key)

[oryaacov]

Summary

• Multi-repo sessions currently have no way to add/remove repos after creation — you must delete and recreate
• This adds a new p hotkey that opens an edit dialog for multi-repo sessions, allowing path changes in-place with automatic session restart

Changes

New file: internal/ui/editpaths_dialog.go (578 lines)

• EditPathsDialog modal for editing paths of an existing multi-repo session
• Path list with add (a), remove (d), edit (Enter), navigate (j/k)
• Tab completion via GetDirectoryCompletions (same as new session dialog)
• Floating suggestions dropdown with overlay rendering and ^N/^P cycling
• Validation: min 2 paths, no duplicates, all paths must exist
• ANSI-aware overlay helpers (overlayDropdown, truncateVisible, sliceVisibleFrom) for z-index style dropdown rendering

internal/ui/home.go

• p hotkey opens the dialog when a multi-repo session is focused
• handleEditPathsDialogKey dispatches Enter/Esc to the dialog
• applyMultiRepoPathChanges rebuilds the symlink directory and restarts the session
• p: Paths hint added to bottom status bar, stopped/error Actions sections, and preview pane Multi-Repo section

internal/ui/hotkeys.go: Registered edit_paths action bound to p (customizable)

internal/ui/help.go: Added "Edit multi-repo paths" to help overlay

How it works

1. User presses p on a multi-repo session
2. Dialog shows current paths (resolved from symlinks back to real paths)
3. User adds/removes/edits paths, confirms with Enter
4. applyMultiRepoPathChanges: clears all symlinks in the session's temp dir, creates new symlinks for updated paths, updates ProjectPath/AdditionalPaths, saves to SQLite, calls Restart() (which does respawn-pane with updated --add-dir flags for Claude)

Test plan

• All existing UI tests pass (47+ tests)
• Clean build on main
• Manual: create multi-repo session with 2 repos, press p, add a 3rd repo, confirm → session restarts with 3 repos
• Manual: edit paths dialog shows path suggestions dropdown
• Manual: remove a repo (must keep ≥2), confirm → session restarts with updated repos
• Manual: verify p key is only active on multi-repo sessions (no-op on single-repo)
• Manual: verify bottom bar shows "Paths" hint only for multi-repo sessions

🤖 Generated with Claude Code