Share completion and add SSH line editing

src/console_completion.h

@@ -12,6 +12,13 @@ extern "C" {
 /* Install late-terminal upgrade handling and project-specific completion. */
 void console_completion_install(void);
 
+typedef bool (*console_completion_visitor_t)(const char *candidate, void *context);
+
+/* Visit the same matching hint candidates used by both UART0 and admin SSH. */
+void console_completion_visit(const char *line,
+                              console_completion_visitor_t visitor,
+                              void *context);
+
 /* Bounded longest-prefix completion shared by the UART and admin SSH frontends. */
 bool console_completion_expand(const char *line, char *completed, size_t capacity);