feat(edit): replace edit wrapper with multi-editor launcher

Rewrite functions/edit.fish as a flexible launcher supporting GUI and
terminal editors with rich fallback chains, clipboard/text temp files,
new-window flags, and verbose/silent output control.

- --visual/--terminal force mode; default auto-detects via tty
- GUI chain: zed → antigravity-ide → code → kate → kwrite → gnome-text-editor → gedit
- Terminal chain: nvim → vim → micro → nano → vi
- --clipboard reuses the existing p function; --text opens a literal string
- --new maps to per-editor new-window flags (best-effort)
- C1 guard falls back to legacy bare-editor behavior when disabled

Docs: update fish-config.md function entry + C1 table, README and AGENTS C1 shadow lists.

README.md

@@ -257,7 +257,7 @@ If you'd rather set them by hand, each category is controlled by a universal var
 
 | Variable | Disables |
 |---|---|
-| `__fish_config_op_aliases` | Command shadows: `ls`→eza, `cat`→bat, `cd`→zoxide, `rm`→trash, `top`→btop, and friends; `grep`/`cp`/`mv`/`wget` flag injection |
+| `__fish_config_op_aliases` | Command shadows: `ls`→eza, `cat`→bat, `cd`→zoxide, `rm`→trash, `top`→btop, `edit`→multi-editor launcher, and friends; `grep`/`cp`/`mv`/`wget` flag injection |
 | `__fish_config_op_autoexec` | Startup side-effects: Fisher bootstrap, theme apply, `paru`/`yay` wrapper generation, auto venv activation, WakaTime hook |
 | `__fish_config_op_overrides` | Vi mode, `exit`→`smart_exit`, `$PAGER`/`$MANPAGER`/`$CDPATH`, bang-bang history expansion, autopair, puffer, Starship prompt, theme colors |
 | `__fish_config_op_integrations` | Kitty/WezTerm window abbreviations, `done` notifications, `spwin`/`tab`/`split`, `hist`, `logs`, `upgrade`, WakaTime |