BC-250 console image: custom GNOME recipe with remote admin

Based on 62fixolab/Latest-Bazzite-AMD-BC-250-Patched-Images @ 347fd4d.

Adds on top of the fork:
- recipes/bc250-console-gnome.yml: governor + gnome-remote-desktop +
  openssh-server, sshd enabled, hhd.service masked, no signing module
  (local build + ISO path)
- files/console/usr/bin/bc250-remote-setup: one-time on-box SSH/RDP setup
- files/console/usr/lib/bootc/kargs.d/50-bc250-ttm.toml: ttm memory kargs
- BUILD-CONSOLE.md: build -> ISO -> validation instructions

files/console/ is separate from files/system/ so the 40-CU unlock tooling
stays out of this stable 24-CU image.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

vendor/bc250-40cu-unlock/scripts/cu_map.sh

@@ -0,0 +1,127 @@
+#!/bin/bash
+# cu_map.sh — Read and display CU bitmap from DRM ioctl via libdrm.
+#
+# Optional health overlay:
+#   ./cu_map.sh --health /var/lib/bc250-cu-health-test/results.tsv
+
+set -euo pipefail
+
+HEALTH="${BC250_CU_HEALTH_RESULTS:-/var/lib/bc250-cu-health-test/results.tsv}"
+
+while [ "$#" -gt 0 ]; do
+    case "$1" in
+        --health)
+            HEALTH="${2:?missing value for --health}"
+            shift 2
+            ;;
+        --no-health)
+            HEALTH=""
+            shift
+            ;;
+        -h|--help)
+            sed -n '1,10p' "$0"
+            exit 0
+            ;;
+        *)
+            echo "ERROR: unknown argument: $1" >&2
+            exit 2
+            ;;
+    esac
+done
+
+BC250_CU_HEALTH_RESULTS="$HEALTH" python3 << 'PYEOF'
+import ctypes, struct, os, sys
+
+libdrm = ctypes.CDLL("libdrm_amdgpu.so.1")
+fd = os.open("/dev/dri/renderD128", os.O_RDWR)
+dev = ctypes.c_void_p()
+maj, min_ = ctypes.c_uint32(), ctypes.c_uint32()
+libdrm.amdgpu_device_initialize(fd, ctypes.byref(maj), ctypes.byref(min_), ctypes.byref(dev))
+
+buf = (ctypes.c_uint8 * 1024)()
+libdrm.amdgpu_query_info(dev, 0x16, 1024, ctypes.byref(buf))
+raw = bytes(buf)
+
+num_se = struct.unpack_from('<I', raw, 20)[0]
+num_sh = struct.unpack_from('<I', raw, 24)[0]
+cu_active = struct.unpack_from('<I', raw, 48)[0]
+
+total = 0
+rows = []
+patterns = []
+for se in range(num_se):
+    for sh in range(num_sh):
+        bm = struct.unpack_from('<I', raw, 56 + (se * 4 + sh) * 4)[0]
+        n = bin(bm).count('1')
+        total += n
+        bar = ''.join('■' if bm & (1 << i) else '□' for i in range(10))
+        # check if disabled CUs are contiguous (all packed at one end)
+        disabled = [i for i in range(10) if not (bm & (1 << i))]
+        if len(disabled) == 0:
+            pattern = "full"
+        elif disabled == list(range(disabled[0], disabled[0] + len(disabled))):
+            pattern = "contiguous"
+        else:
+            pattern = "scattered"
+        rows.append(f"SE{se} SH{sh}: {bar}")
+        patterns.append(pattern)
+
+possible = num_se * num_sh * 10
+harvested = possible - total
+print()
+health_path = os.environ.get("BC250_CU_HEALTH_RESULTS", "")
+health = {}
+if health_path and os.path.exists(health_path):
+    with open(health_path, "r", encoding="utf-8") as f:
+        for line in f:
+            line = line.strip()
+            if not line or line.startswith("#"):
+                continue
+            parts = line.split("\t")
+            if len(parts) < 5:
+                continue
+            _idx, se, sh, wgp, status = parts[:5]
+            try:
+                health[(int(se), int(sh), int(wgp))] = status
+            except ValueError:
+                continue
+
+print("BC-250 CU Map" + (" + Health" if health else ""))
+for r in rows:
+    print(r)
+print(f"{total}/{possible} CUs active, {harvested} harvested")
+
+if health:
+    usable = 0
+    failed = 0
+    print()
+    print("BC-250 CU Map + Health")
+    for se in range(num_se):
+        for sh in range(num_sh):
+            glyphs = []
+            for cu in range(10):
+                wgp = cu // 2
+                status = health.get((se, sh, wgp))
+                if status == "FAIL":
+                    glyphs.append("✗")
+                elif cu < 6:
+                    glyphs.append("■")
+                elif status == "PASS":
+                    glyphs.append("✓")
+                else:
+                    glyphs.append("?")
+            for wgp in range(5):
+                status = health.get((se, sh, wgp))
+                if status == "FAIL":
+                    failed += 2
+                elif wgp < 3 or status == "PASS":
+                    usable += 2
+            print(f"SE{se} SH{sh}: {''.join(glyphs)}")
+    print(f"{usable}/{possible} CUs usable ({failed} defective, masked)")
+elif health_path:
+    print()
+    print(f"Health overlay: no results file found at {health_path}")
+
+libdrm.amdgpu_device_deinitialize(dev)
+os.close(fd)
+PYEOF