feat: Add optional Logfire observability to sync operations

Add Logfire as a dependency for performance instrumentation. Logfire is
disabled by default (via ignore_no_config) and only activates when
LOGFIRE_TOKEN is set, keeping the FOSS version telemetry-free.

Changes:
- Added logfire>=0.73.0 as dependency
- Instrumented sync_file() and sync_markdown_file() with @logfire.instrument()
- Logfire captures function arguments and timing automatically
- No changes to behavior when LOGFIRE_TOKEN is not set

This will help diagnose performance bottlenecks in sync operations,
particularly for understanding the 28% slowdown in initial sync compared
to baseline (50.4ms vs 39.3ms per file).

Related: SPEC-19 Phase 1 performance analysis

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>
Signed-off-by: phernandez <paul@basicmachines.co>

Author: phernandez

pyproject.toml

@@ -35,6 +35,7 @@ dependencies = [
     "python-dotenv>=1.1.0",
     "pytest-aio>=1.9.0",
     "aiofiles>=24.1.0", # Async file I/O
+    "logfire>=0.73.0", # Optional observability (disabled by default via config)
 ]
 
 

src/basic_memory/sync/sync_service.py

@@ -9,6 +9,7 @@
 from pathlib import Path
 from typing import AsyncIterator, Dict, List, Optional, Set, Tuple
 
+import logfire
 from loguru import logger
 from sqlalchemy.exc import IntegrityError
 
@@ -495,6 +496,7 @@ async def scan(self, directory):
         )
         return report
 
+    @logfire.instrument()
     async def sync_file(
         self, path: str, new: bool = True
     ) -> Tuple[Optional[Entity], Optional[str]]:
@@ -549,6 +551,7 @@ async def sync_file(
 
             return None, None
 
+    @logfire.instrument()
     async def sync_markdown_file(self, path: str, new: bool = True) -> Tuple[Optional[Entity], str]:
         """Sync a markdown file with full processing.