feat(web): inline URL import input, no pane

[diogobaltazar]

Description

The "Import from URL" action currently opens a pane or toolbar overlay. Instead, it should render an inline text input in the same style as the search:activity input — appearing in-place in the command bar area without opening a separate pane or sheet.

Motivation

Panes interrupt flow and feel heavy for a single text entry. The activity search pattern proves a lightweight inline input works well in this shell.

Acceptance criteria

• Clicking the URL import dock button reveals an inline text input (styled like the search:activity input) rather than opening a pane or toolbar overlay.
• The input accepts a URL, and submitting triggers the existing import logic.
• Pressing Escape dismisses the input without importing.
• The existing url-import-toolbar overlay/pane is removed.
• No other application behaviour changes.