Add Jinja template support

[ochafik]

Subset of #9639 with just the Jinja templating support.

Proper tool support (grammar constraints, lazy grammar triggering, tool call parsing & stop reason) will come in a follow up PR.

• Copies minja.hpp & chat-template.hpp from google/minja (created for this 😅) at this commit
• Adds --jinja flag to llama-server, llama-cli, llama-run
• Adds --chat-template-file flag to llama-server, llama-cli (related: Added chat template support to llama-run #11215 )
• Loads tokenizer.chat_template (or tokenizer.chat_template.tool_use if defined, only when the request has tools).
• Dual testing in test-chat-template.cpp of legacy adhoc templating & jinja route. Wherever the expected outputs diverge, the jinja expectations should be more correct (note that templates are run w/ trim_blocks = true, lstrip_blocks = true)
  • Sent Refactor test-chat-template.cpp #11224 separately

Example usage:

# Launch in background
./build/bin/llama-server \
  -hfr bartowski/Qwen2.5-7B-Instruct-GGUF \
  -hff Qwen2.5-7B-Instruct-Q4_K_M.gguf \
  --jinja &

curl http://localhost:8080/v1/chat/completions \
  -d '{
    "model": "gpt-3.5-turbo",
    "tools": [
      {
        "type": "function",
        "function": {
          "name": "ipython",
          "description": "Runs code in an ipython interpreter and returns the result of the execution after 60 seconds.",
          "parameters": {
            "type": "object",
            "properties": {
              "code": {
                "type": "string",
                "description": "The code to run in the ipython interpreter."
              }
            },
            "required": ["code"]
          }
        }
      }
    ],
    "messages": [
      {
        "role": "user",
        "content": "Print a hello world message with python (using single quotes '"'"' for strings)."
      }
    ]
  }'

show output

{
  "choices": [
    {
      "finish_reason": "stop",
      "index": 0,
      "message": {
        "content": "<tool_call>\n{\"name\": \"ipython\", \"arguments\": {\"code\": \"print('Hello world!')\"}}\n</tool_call>",
        "role": "assistant"
      }
    }
  ],
  "created": 1736811609,
  "model": "gpt-3.5-turbo",
  "system_fingerprint": "b4494-a57bb94e",
  "object": "chat.completion",
  "usage": {
    "completion_tokens": 25,
    "prompt_tokens": 205,
    "total_tokens": 230
  },
  "id": "chatcmpl-5YJXFVhvjoMDlLx1asuWNdSO3JVWWsUF",
  "timings": {
    "prompt_n": 1,
    "prompt_ms": 155.151,
    "prompt_per_token_ms": 155.151,
    "prompt_per_second": 6.445333900522716,
    "predicted_n": 25,
    "predicted_ms": 419.714,
    "predicted_per_token_ms": 16.78856,
    "predicted_per_second": 59.56437002339688
  }
}

TODO:

• Add cross-testing in test-chat-template.cpp (note that minja is tested against a lot of templates in its own repo)
• Add some instructions here
• Add more server tests to exercise the template overrides.

[ericcurtin]

Feel free to add the option to llama-run for basic testing also @ochafik

[ericcurtin]

I approve the llama-run parts at least, but the more code we can share with llama-server, etc. the better, there's probably room for more de-duplication

[ngxson]

IMO we can extend common_chat_apply_template to add bool jinja and reuse this function in other examples.