Autoparser - complete refactoring of parser architecture (#18675)

* Autoparser - full single commit squish

* Final pre-merge changes: minor fixes, Kimi 2.5 model parser

common/unicode.h

@@ -2,6 +2,8 @@
 
 #include <cstdint>
 #include <string_view>
+#include <vector>
+#include <string>
 
 // UTF-8 parsing utilities for streaming-aware unicode support
 
@@ -16,7 +18,10 @@ struct utf8_parse_result {
 
 // Determine the expected length of a UTF-8 sequence from its first byte
 // Returns 0 for invalid first bytes
-size_t utf8_sequence_length(unsigned char first_byte);
+size_t common_utf8_sequence_length(unsigned char first_byte);
 
 // Parse a single UTF-8 codepoint from input
-utf8_parse_result parse_utf8_codepoint(std::string_view input, size_t offset);
+utf8_parse_result common_parse_utf8_codepoint(std::string_view input, size_t offset);
+
+std::string common_unicode_cpts_to_utf8(const std::vector<uint32_t> & cps);
+std::string common_unicode_cpt_to_utf8(uint32_t cpt);