Fix mypy type errors in compression module

- Fix compress_with_llmlingua call: use compression_rate parameter
- Fix CompressionStore.store() call: use positional args for original/compressed
- Fix extract_json_schema return type to support arrays
- Add proper type casts for Any returns

headroom/compression/handlers/json_handler.py

@@ -15,7 +15,7 @@ from __future__ import annotations
 import json
 from dataclasses import dataclass
 from enum import Enum
-from typing import Any
+from typing import Any, cast
 
 from headroom.compression.handlers.base import BaseStructureHandler, HandlerResult
 from headroom.compression.masks import EntropyScore, StructureMask
@@ -370,7 +370,7 @@ class JSONStructureHandler(BaseStructureHandler):
         return tokens
 
 
-def extract_json_schema(content: str) -> dict[str, Any]:
+def extract_json_schema(content: str) -> dict[str, Any] | list[Any]:
     """Extract the schema (keys only) from JSON content.
 
     Useful for understanding the structure without the values.
@@ -408,6 +408,11 @@ def extract_json_schema(content: str) -> dict[str, Any]:
 
     try:
         parsed = json.loads(content)
-        return _extract(parsed)
+        result = _extract(parsed)
+        if isinstance(result, dict):
+            return cast(dict[str, Any], result)
+        elif isinstance(result, list):
+            return cast(list[Any], result)
+        return {}
     except (json.JSONDecodeError, ValueError):
         return {}

headroom/compression/universal.py

@@ -187,11 +187,10 @@ class UniversalCompressor:
         try:
             from headroom.transforms.llmlingua_compressor import compress_with_llmlingua
 
-            result = compress_with_llmlingua(
+            return compress_with_llmlingua(
                 text,
-                target_ratio=self.config.compression_ratio_target,
+                compression_rate=self.config.compression_ratio_target,
             )
-            return result.compressed
         except ImportError:
             return self._simple_compress(text)
         except Exception as e:
@@ -371,8 +370,8 @@ class UniversalCompressor:
                 self._ccr_store = CompressionStore()
 
             key = self._ccr_store.store(
-                original_content=original,
-                compressed_content=compressed,
+                original,
+                compressed,
                 original_tokens=self._estimate_tokens(original),
                 compressed_tokens=self._estimate_tokens(compressed),
             )