feat(terminal): detect localhost URLs in PTY output and show preview banner

[dcieslak19973]

Summary

When a process running in a terminal pane prints a localhost URL to stdout/stderr (e.g. npm run dev printing http://localhost:5173), a dismissible banner appears at the bottom of that pane with a clickable URL and an Open in Preview button that loads it in the built-in preview tab.

Changes

New files

• src/modules/terminal/lib/url-detector.ts — pure function that decodes raw PTY bytes, strips ANSI escape sequences, and matches http(s)://localhost:PORT / http(s)://127.0.0.1:PORT URLs. Requires an explicit port. Flags OAuth-style redirect URLs (/callback, ?code=, etc.) for a distinct icon.
• src/modules/terminal/LocalUrlBanner.tsx — absolute-positioned overlay rendered inside the terminal pane. Shows a Key01Icon (amber) for OAuth hints or Link01Icon (blue) for plain servers, the truncated URL, an Open in Preview button, and a dismiss button. Auto-dismisses after 30 s.

Modified files

• useTerminalSession.ts — calls extractLocalhostUrls alongside deliverPtyBytes in the onData callback; per-session seenUrls: Set<string> prevents re-firing the same URL; onUrl callback added to Callbacks and Options types; seenUrls reset in respawnSession.
• TerminalPane.tsx — wraps the xterm container in a relative div, manages banner state, passes onUrl to useTerminalSession, renders <LocalUrlBanner> overlay, accepts new onOpenUrl prop.
• PaneTreeView.tsx / TerminalStack.tsx — onOpenUrl threaded through the bundle chain (LeafBundle / Bundle types updated).
• App.tsx — onOpenUrl={(_, url) => openPreviewTab(url)} added to <TerminalStack>.

UX behaviour

• Banner appears once per unique URL per terminal session (deduped via seenUrls)
• Clicking the URL text or Open in Preview opens the URL in a preview tab and dismisses the banner
• Banner auto-dismisses after 30 seconds
• Respawning the session (e.g. after the process exits) resets seenUrls so the URL can surface again