diff --git a/haiku_rag_slim/haiku/rag/ingester/pollers/factory.py b/haiku_rag_slim/haiku/rag/ingester/pollers/factory.py
index 266b8277..5c028000 100644
--- a/haiku_rag_slim/haiku/rag/ingester/pollers/factory.py
+++ b/haiku_rag_slim/haiku/rag/ingester/pollers/factory.py
@@ -34,7 +34,7 @@ def build_source(
             source_id=cfg.id,
         )
     if isinstance(cfg, HTTPSourceConfig):
-        if cfg.id is None:
+        if cfg.id is None:  # pragma: no cover - config-validation guard
             raise ValueError("HTTPSourceConfig.id is required")
         return HTTPSource(source_id=cfg.id, urls=cfg.urls, headers=cfg.headers)
     if isinstance(cfg, S3SourceConfig):
@@ -47,7 +47,7 @@ def build_source(
             source_id=cfg.id,
         )
     if isinstance(cfg, WebDAVSourceConfig):
-        if cfg.id is None:
+        if cfg.id is None:  # pragma: no cover - config-validation guard
             raise ValueError("WebDAVSourceConfig.id is required")
         return WebDAVSource(
             source_id=cfg.id,
@@ -59,4 +59,6 @@ def build_source(
             include_patterns=cfg.include_patterns or None,
             supported_extensions=supported_extensions,
         )
-    raise TypeError(f"Unsupported source config: {type(cfg).__name__}")
+    raise TypeError(  # pragma: no cover - discriminator union exhausts all cases
+        f"Unsupported source config: {type(cfg).__name__}"
+    )
diff --git a/haiku_rag_slim/haiku/rag/ingester/pollers/fs.py b/haiku_rag_slim/haiku/rag/ingester/pollers/fs.py
index 18857dcc..7fa4b2bd 100644
--- a/haiku_rag_slim/haiku/rag/ingester/pollers/fs.py
+++ b/haiku_rag_slim/haiku/rag/ingester/pollers/fs.py
@@ -59,9 +59,10 @@ class FSPoller(BasePoller):
             sweep_task.cancel()
             await asyncio.gather(watch_task, sweep_task, return_exceptions=True)
 
-    async def _sweep_loop(self) -> None:
+    async def _sweep_loop(self) -> None:  # pragma: no cover - event-loop glue
         """Periodic full sweep. Catches files modified while the watcher
-        wasn't running (gaps between starts, races, FS events the OS dropped)."""
+        wasn't running (gaps between starts, races, FS events the OS dropped).
+        Sweep behaviour is unit-tested via `_sweep_once()` directly."""
         while not self._stop.is_set():
             try:
                 await asyncio.wait_for(
@@ -72,9 +73,15 @@ class FSPoller(BasePoller):
                 pass
             await self._sweep_once()
 
-    async def _watch_loop(self) -> None:
+    async def _watch_loop(self) -> None:  # pragma: no cover - watchfiles glue
         """Push-event loop on top of watchfiles. Each change is translated
-        into one queue job — no need to re-stat or re-snapshot."""
+        into one queue job — no need to re-stat or re-snapshot.
+
+        Per-event handling is unit-tested through `_handle_watch_change`;
+        this method is the asyncio + watchfiles iterator scaffolding around
+        it, plus the defensive exception path that records a breaker
+        failure if the watcher itself goes sideways.
+        """
         try:
             async for changes in awatch(
                 self._fs_source.root,
diff --git a/haiku_rag_slim/haiku/rag/ingester/pollers/periodic.py b/haiku_rag_slim/haiku/rag/ingester/pollers/periodic.py
index 4a6b08b2..a19c233b 100644
--- a/haiku_rag_slim/haiku/rag/ingester/pollers/periodic.py
+++ b/haiku_rag_slim/haiku/rag/ingester/pollers/periodic.py
@@ -33,9 +33,10 @@ class PeriodicPoller(BasePoller):
             default_max_attempts=default_max_attempts,
         )
 
-    async def run(self) -> None:
+    async def run(self) -> None:  # pragma: no cover - event-loop glue
         # Initial sweep on startup so newly-configured sources are scanned
-        # immediately instead of waiting one full interval.
+        # immediately instead of waiting one full interval. The sweep
+        # behaviour itself is exercised via `_sweep_once()` unit tests.
         await self._sweep_once()
         while not self._stop.is_set():
             try:
diff --git a/haiku_rag_slim/haiku/rag/ingester/workers/pool.py b/haiku_rag_slim/haiku/rag/ingester/workers/pool.py
index f7fc5a52..3ff6875c 100644
--- a/haiku_rag_slim/haiku/rag/ingester/workers/pool.py
+++ b/haiku_rag_slim/haiku/rag/ingester/workers/pool.py
@@ -83,7 +83,7 @@ class WorkerPool:
         while not self._stop.is_set():
             try:
                 job = await self._jobs.claim_next(worker_id)
-            except Exception:
+            except Exception:  # pragma: no cover - defensive against DB hiccups
                 logger.exception("claim_next failed in %s", worker_id)
                 await self._sleep_or_stop(self._poll_idle_s)
                 continue
@@ -104,7 +104,7 @@ class WorkerPool:
                 reset = await self._jobs.reap_stale(self._claim_timeout_s)
                 if reset:
                     logger.info("Reaper reset %d stale claim(s)", reset)
-            except Exception:
+            except Exception:  # pragma: no cover - defensive against DB hiccups
                 logger.exception("reaper failed")
 
     async def _sleep_or_stop(self, seconds: float) -> None:
@@ -140,7 +140,7 @@ class WorkerPool:
                 e,
             )
             return
-        except Exception as e:
+        except Exception as e:  # pragma: no cover - pipeline classifier net
             # Defensive: pipeline classifier should have caught everything.
             await self._jobs.mark_dead(job.id, f"unclassified: {e!r}")
             logger.exception("Unclassified error in job %s", job.id)