T45: round 1 fix: herdr's client opens only http and https links, so inside herdr a link the app finds of another kind, file:// among them, the app opens itself; web links and links the app cannot see still go to herdr

PRD.md

@@ -58,7 +58,7 @@ Ghostty is the bar for what the terminal does. ELYTerminal owns its engine on `a
 - IME: marked text drawn at the cursor; committed text sent to the program.
 - Mouse: select by character, word (double press) and line (triple press); Shift extends; mouse reporting (X10, normal, button, any; SGR and UTF-8); wheel scrolls back, or reports, or sends arrows on the alternate screen.
 - Clipboard: copy, paste (bracketed when asked), copy on select per setting, OSC 52 writes.
-- Links: OSC 8 and plain URLs; Cmd-press (Ctrl-press off macOS) opens them. Inside herdr, herdr opens them, whole where its pane wraps them, and underlines them while the key is held.
+- Links: OSC 8 and plain URLs; Cmd-press (Ctrl-press off macOS) opens them. Inside herdr, herdr opens web links, whole where its pane wraps them, and underlines them while the key is held; a link of another kind the terminal opens itself.
 - Focus reporting, title (OSC 0/2), scrollback limit per setting, find in scrollback (Ely's `FindWidget`).
 - Bell: no sound. The session row marks it until the session is shown.