Add OLED and button diagnostics

src/console_completion.c

@@ -24,6 +24,33 @@ static const char *const s_completion_candidates[] = {
     "debug uart-suite",
     "debug cts-flow-test",
     "debug rts-flow-test",
+    "debug display",
+    "debug display status",
+    "debug display probe",
+    "debug display scan",
+    "debug display scan --force",
+    "debug display init",
+    "debug display init 0x3c",
+    "debug display init 0x78",
+    "debug display init 0x79",
+    "debug display init 0x3d",
+    "debug display init 0x7a",
+    "debug display init 0x7b",
+    "debug display off",
+    "debug display pattern",
+    "debug display pattern clear",
+    "debug display pattern fill",
+    "debug display pattern checker",
+    "debug display pattern grid",
+    "debug display pattern corners",
+    "debug display row",
+    "debug display contrast",
+    "debug display invert",
+    "debug display invert on",
+    "debug display invert off",
+    "debug buttons",
+    "debug buttons status",
+    "debug buttons test",
 
     /* Serial service lifecycle, persistence, counters, and settings. */
     "serial status",