feat: new summary using phi-4 and llama-index (#519)

* feat: add litellm backend implementation

* refactor: improve generate/completion methods for base LLM

* refactor: remove tokenizer logic

* style: apply code formatting

* fix: remove hallucinations from LLM responses

* refactor: comprehensive LLM and summarization rework

* chore: remove debug code

* feat: add structured output support to LiteLLM

* refactor: apply self-review improvements

* docs: add model structured output comments

* docs: update model structured output comments

* style: apply linting and formatting fixes

* fix: resolve type logic bug

* refactor: apply PR review feedback

* refactor: apply additional PR review feedback

* refactor: apply final PR review feedback

* fix: improve schema passing for LLMs without structured output

* feat: add PR comments and logger improvements

* docs: update README and add HTTP logging

* feat: improve HTTP logging

* feat: add summary chunking functionality

* fix: resolve title generation runtime issues

* refactor: apply self-review improvements

* style: apply linting and formatting

* feat: implement LiteLLM class structure

* style: apply linting and formatting fixes

* docs: env template model name fix

* chore: remove older litellm class

* chore: format

* refactor: simplify OpenAILLM

* refactor: OpenAILLM tokenizer

* refactor: self-review

* refactor: self-review

* refactor: self-review

* chore: format

* chore: remove LLM_USE_STRUCTURED_OUTPUT from envs

* chore: roll back migration lint changes

* chore: roll back migration lint changes

* fix: make summary llm configuration optional for the tests

* fix: missing f-string

* fix: tweak the prompt for summary title

* feat: try llamaindex for summarization

* fix: complete refactor of summary builder using llamaindex and structured output when possible

* fix: separate prompt as constant

* fix: typings

* fix: enhance prompt to prevent mentioning others subject while summarize one

* fix: various changes after self-review

* fix: from igor review

---------

Co-authored-by: Igor Loskutov <igor.loskutoff@gmail.com>

server/pyproject.toml

@@ -38,6 +38,8 @@ dependencies = [
     "jsonschema>=4.23.0",
     "openai>=1.59.7",
     "psycopg2-binary>=2.9.10",
+    "llama-index>=0.12.52",
+    "llama-index-llms-openai-like>=0.4.0",
 ]
 
 [dependency-groups]