[Feature] SFTP: allow typing a specific path to jump to a directory

[thangnm93]

Problem Statement

The SFTP file panels (remote and local) only support navigation by clicking breadcrumb segments or double-clicking directory entries. Reaching a deep directory (e.g. /var/lib/docker/volumes/...) takes many clicks, and there is no way to paste a known path and jump straight to it. Anyone who already knows the target path is slowed down.

Proposed Solution

Add an inline path editor to the shared PathBreadcrumb widget:

• A "Go to path" edit affordance next to the breadcrumb opens a text field seeded with the current path
• Enter navigates to the typed path; Escape (or clicking outside) cancels
• Available in both the remote SFTP panel and the local file panel
• Remote input normalized to absolute POSIX (leading / enforced, trailing slash dropped)
• Invalid paths surface through the existing panel error state

Alternatives Considered

• Separate "Go to path" dialog (like New Folder / Rename) — an extra modal hop for a navigation action; inline editing on the breadcrumb is one click and keeps spatial context
• Making the breadcrumb always an editable text field (Finder-style toggle only) — loses the one-click segment navigation that already works well

Additional Context

Implemented in #61 (PathBreadcrumb gains an editablePath parameter; both panels pass their provider's currentPath). Covered by widget tests: editor reveal/seed, submit navigates, blank submit ignored, Escape cancels.