Added — real setup wizards for the three secondary OSes
Each `Platform.setup()` in `src/trcc/next/` previously logged a "not yet wired" warning. Each is now a real wizard tailored to the OS's actual permission model — researched against current platform documentation, written so the script can never silently break a working install.
- FreeBSD (`_devd.py`): generates `/usr/local/etc/devd/trcc.conf` with `chmod 0666` rules for every TRCC VID:PID, atomic write, then `service devd restart`. Re-execs via `sudo` or `doas` when called as a normal user.
- Windows (`_winusb.py`): read-only diagnostic — splits connected devices into "visible to pyusb" vs "needs WinUSB", prints a copy-paste Zadig recipe naming each missing device. Catches the missing-libusb-1.0.dll case separately.
- macOS (`_macos_setup.py`): read-only diagnostic — checks codesign / quarantine xattr / privilege state, prints the matching fix (Gatekeeper Open Anyway, `xattr -d`, or `sudo` re-run).
The asymmetry mirrors the platforms themselves: BSD writes rules, macOS just diagnoses (entitlements need an Apple Developer ID), Windows needs the user to run Zadig (UAC + signed driver package). The wizard does whatever each OS actually allows — never more, never less, never silently.
Pure Python; no legacy or shipping behaviour changed; gap filled only in the experimental `TRCC_NEXT=1` build.