feat: add OpenTelemetry distributed tracing across all DECNET services

Gated by DECNET_DEVELOPER_TRACING env var (default off, zero overhead).
When enabled, traces flow through FastAPI routes, background workers
(collector, ingester, profiler, sniffer, prober), engine/mutator
operations, and all DB calls via TracedRepository proxy.

Includes Jaeger docker-compose for local dev and 18 unit tests.

decnet/web/api.py

@@ -50,6 +50,10 @@ async def lifespan(app: FastAPI) -> AsyncGenerator[None, None]:
                 log.error("DB failed to initialize after 5 attempts — startup may be degraded")
             await asyncio.sleep(0.5)
 
+    # Conditionally enable OpenTelemetry tracing
+    from decnet.telemetry import setup_tracing
+    setup_tracing(app)
+
     # Start background tasks only if not in contract test mode
     if os.environ.get("DECNET_CONTRACT_TEST") != "true":
         # Start background ingestion task
@@ -99,6 +103,8 @@ async def lifespan(app: FastAPI) -> AsyncGenerator[None, None]:
                 pass
             except Exception as exc:
                 log.warning("Task shutdown error: %s", exc)
+    from decnet.telemetry import shutdown_tracing
+    shutdown_tracing()
     log.info("API shutdown complete")
 
 

decnet/web/db/factory.py

@@ -22,8 +22,12 @@ def get_repository(**kwargs: Any) -> BaseRepository:
 
     if db_type == "sqlite":
         from decnet.web.db.sqlite.repository import SQLiteRepository
-        return SQLiteRepository(**kwargs)
-    if db_type == "mysql":
+        repo = SQLiteRepository(**kwargs)
+    elif db_type == "mysql":
         from decnet.web.db.mysql.repository import MySQLRepository
-        return MySQLRepository(**kwargs)
-    raise ValueError(f"Unsupported database type: {db_type}")
+        repo = MySQLRepository(**kwargs)
+    else:
+        raise ValueError(f"Unsupported database type: {db_type}")
+
+    from decnet.telemetry import wrap_repository
+    return wrap_repository(repo)

decnet/web/ingester.py

@@ -5,6 +5,7 @@ from typing import Any
 from pathlib import Path
 
 from decnet.logging import get_logger
+from decnet.telemetry import traced as _traced
 from decnet.web.db.repository import BaseRepository
 
 logger = get_logger("api")
@@ -83,6 +84,7 @@ async def log_ingestion_worker(repo: BaseRepository) -> None:
         await asyncio.sleep(1)
 
 
+@_traced("ingester.extract_bounty")
 async def _extract_bounty(repo: BaseRepository, log_data: dict[str, Any]) -> None:
     """Detect and extract valuable artifacts (bounties) from log entries."""
     _fields = log_data.get("fields")