Initial commit: JCD3198 second HDMI driver setup for Fedora

Enables the MCT T6 USB Station (0711:5601) chip on the J5 Create JCD3198
dock, which drives the 4K30 HDMI port with no native Linux kernel driver.

Stack: EVDI 1.14.16 (kernel module + libevdi) → t6evdi userspace daemon
(mobilepixels-linux-driver, patched for EVDI 1.14 API) → MCT T6 over USB.

Includes DKMS registration for evdi.ko (auto-rebuilds on kernel updates)
and a Mutter D-Bus layout script that restores monitor positions by serial
number after each daemon restart, working around the incrementing DVI-I-N
connector name assigned by EVDI on every reconnect.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

bin/fix-monitor-layout

@@ -0,0 +1,85 @@
+#!/usr/bin/env python3
+"""Re-apply dual-monitor layout after t6evdi restarts.
+
+Matches monitors by serial number (not connector name), so it works
+regardless of what DRM connector name t6evdi assigns on each restart.
+
+LG FHD  (GSM, serial 0x01010101) → left  (x=0)
+Acer SA270 (ACR, serial 0x13102591) → right (x=1920), primary
+"""
+
+import sys
+import dbus
+
+BUS = 'org.gnome.Mutter.DisplayConfig'
+PATH = '/org/gnome/Mutter/DisplayConfig'
+
+LG_SERIAL = '0x01010101'
+ACER_SERIAL = '0x13102591'
+
+
+def find_mode(modes, width=1920, height=1080, rate=74.973):
+    """Return mode ID matching resolution+rate, falling back to resolution only."""
+    for mode_id, mw, mh, mr, *_ in modes:
+        if int(mw) == width and int(mh) == height and abs(float(mr) - rate) < 0.5:
+            return str(mode_id)
+    for mode_id, mw, mh, *_ in modes:
+        if int(mw) == width and int(mh) == height:
+            return str(mode_id)
+    return None
+
+
+def main():
+    try:
+        bus = dbus.SessionBus()
+    except dbus.exceptions.DBusException as e:
+        print(f"ERROR: cannot connect to session bus: {e}", file=sys.stderr)
+        sys.exit(1)
+
+    proxy = bus.get_object(BUS, PATH)
+    iface = dbus.Interface(proxy, BUS)
+
+    serial, monitors, _, _ = iface.GetCurrentState()
+
+    connectors = {}
+    mode_ids = {}
+
+    for (connector, vendor, product, mon_serial), modes, props in monitors:
+        s = str(mon_serial)
+        if s in (LG_SERIAL, ACER_SERIAL):
+            connectors[s] = str(connector)
+            mode_ids[s] = find_mode(modes)
+
+    errors = []
+    for label, key in [('LG FHD', LG_SERIAL), ('Acer SA270', ACER_SERIAL)]:
+        if key not in connectors:
+            errors.append(f"{label} not detected")
+        elif mode_ids[key] is None:
+            errors.append(f"no 1920x1080 mode on {label}")
+    if errors:
+        print(f"ERROR: {'; '.join(errors)}", file=sys.stderr)
+        sys.exit(1)
+
+    logical = [
+        (0, 0, 1.0, 0, False,
+         [(connectors[LG_SERIAL], mode_ids[LG_SERIAL], {})]),
+        (1920, 0, 1.0, 0, True,
+         [(connectors[ACER_SERIAL], mode_ids[ACER_SERIAL], {})]),
+    ]
+
+    iface.ApplyMonitorsConfig(
+        dbus.UInt32(serial),
+        dbus.UInt32(2),  # 2 = persistent
+        logical,
+        {},
+        signature='uua(iiduba(ssa{sv}))a{sv}'
+    )
+
+    print(
+        f"Applied: {connectors[LG_SERIAL]} (LG FHD) at x=0, "
+        f"{connectors[ACER_SERIAL]} (Acer SA270) at x=1920 [primary]"
+    )
+
+
+if __name__ == '__main__':
+    main()