diff --git a/dist/app.py b/dist/app.py
index 9d378d5..088db4b 100644
--- a/dist/app.py
+++ b/dist/app.py
@@ -16043,18 +16043,19 @@ async def _stream():
                 last_seq = ev.seq
                 yield f"data: {envelope.model_dump_json()}\n\n"
             # Tail: poll for new rows. Bounded by client-disconnect.
-            try:
-                while not await request.is_disconnected():
-                    await _asyncio.sleep(0.25)
-                    for ev in event_log.iter_for(session_id, since=last_seq):
-                        envelope = EventEnvelope(
-                            seq=ev.seq, session_id=ev.session_id,
-                            kind=ev.kind, payload=ev.payload, ts=ev.ts,
-                        )
-                        last_seq = ev.seq
-                        yield f"data: {envelope.model_dump_json()}\n\n"
-            except _asyncio.CancelledError:
-                return
+            # CancelledError (from task cancellation, e.g. when the
+            # client closes the connection) propagates naturally — no
+            # try/except needed; suppressing it would break asyncio's
+            # cancellation contract (Sonar python:S7497).
+            while not await request.is_disconnected():
+                await _asyncio.sleep(0.25)
+                for ev in event_log.iter_for(session_id, since=last_seq):
+                    envelope = EventEnvelope(
+                        seq=ev.seq, session_id=ev.session_id,
+                        kind=ev.kind, payload=ev.payload, ts=ev.ts,
+                    )
+                    last_seq = ev.seq
+                    yield f"data: {envelope.model_dump_json()}\n\n"
 
         return StreamingResponse(_stream(), media_type="text/event-stream")
 
diff --git a/dist/apps/code-review.py b/dist/apps/code-review.py
index 343544f..40defdf 100644
--- a/dist/apps/code-review.py
+++ b/dist/apps/code-review.py
@@ -16096,18 +16096,19 @@ async def _stream():
                 last_seq = ev.seq
                 yield f"data: {envelope.model_dump_json()}\n\n"
             # Tail: poll for new rows. Bounded by client-disconnect.
-            try:
-                while not await request.is_disconnected():
-                    await _asyncio.sleep(0.25)
-                    for ev in event_log.iter_for(session_id, since=last_seq):
-                        envelope = EventEnvelope(
-                            seq=ev.seq, session_id=ev.session_id,
-                            kind=ev.kind, payload=ev.payload, ts=ev.ts,
-                        )
-                        last_seq = ev.seq
-                        yield f"data: {envelope.model_dump_json()}\n\n"
-            except _asyncio.CancelledError:
-                return
+            # CancelledError (from task cancellation, e.g. when the
+            # client closes the connection) propagates naturally — no
+            # try/except needed; suppressing it would break asyncio's
+            # cancellation contract (Sonar python:S7497).
+            while not await request.is_disconnected():
+                await _asyncio.sleep(0.25)
+                for ev in event_log.iter_for(session_id, since=last_seq):
+                    envelope = EventEnvelope(
+                        seq=ev.seq, session_id=ev.session_id,
+                        kind=ev.kind, payload=ev.payload, ts=ev.ts,
+                    )
+                    last_seq = ev.seq
+                    yield f"data: {envelope.model_dump_json()}\n\n"
 
         return StreamingResponse(_stream(), media_type="text/event-stream")
 
diff --git a/dist/apps/incident-management.py b/dist/apps/incident-management.py
index 083c713..563f9b4 100644
--- a/dist/apps/incident-management.py
+++ b/dist/apps/incident-management.py
@@ -16108,18 +16108,19 @@ async def _stream():
                 last_seq = ev.seq
                 yield f"data: {envelope.model_dump_json()}\n\n"
             # Tail: poll for new rows. Bounded by client-disconnect.
-            try:
-                while not await request.is_disconnected():
-                    await _asyncio.sleep(0.25)
-                    for ev in event_log.iter_for(session_id, since=last_seq):
-                        envelope = EventEnvelope(
-                            seq=ev.seq, session_id=ev.session_id,
-                            kind=ev.kind, payload=ev.payload, ts=ev.ts,
-                        )
-                        last_seq = ev.seq
-                        yield f"data: {envelope.model_dump_json()}\n\n"
-            except _asyncio.CancelledError:
-                return
+            # CancelledError (from task cancellation, e.g. when the
+            # client closes the connection) propagates naturally — no
+            # try/except needed; suppressing it would break asyncio's
+            # cancellation contract (Sonar python:S7497).
+            while not await request.is_disconnected():
+                await _asyncio.sleep(0.25)
+                for ev in event_log.iter_for(session_id, since=last_seq):
+                    envelope = EventEnvelope(
+                        seq=ev.seq, session_id=ev.session_id,
+                        kind=ev.kind, payload=ev.payload, ts=ev.ts,
+                    )
+                    last_seq = ev.seq
+                    yield f"data: {envelope.model_dump_json()}\n\n"
 
         return StreamingResponse(_stream(), media_type="text/event-stream")
 
diff --git a/sonar-project.properties b/sonar-project.properties
index 3c31a9f..53a01b4 100644
--- a/sonar-project.properties
+++ b/sonar-project.properties
@@ -26,10 +26,23 @@ sonar.test.exclusions=tests/fixtures/**
 #     ``skill.kind``. Same pattern as gateway above.
 sonar.cpd.exclusions=src/runtime/tools/gateway.py,src/runtime/agents/responsive.py
 
-# Coverage exclusions — UI is excluded because Streamlit rendering is exercised
-# manually in a browser, not by the unit-test suite. Coverage gates apply to
-# the framework core (src/runtime/) only.
-sonar.coverage.exclusions=src/runtime/__init__.py,examples/**/ui.py,ui/**
+# Coverage exclusions — kept in sync with [tool.coverage.run].omit in
+# pyproject.toml so the local CI gate and the SonarCloud gate agree on
+# which files are measurement targets:
+#   * ``src/runtime/ui.py`` — 1573-line Streamlit shell, exercised
+#     manually in a browser, not by the unit-test suite. Pending a
+#     dedicated UI-testing milestone.
+#   * ``src/runtime/__main__.py`` — argparse-only CLI entry; smoke-tested
+#     by hand, not pytest.
+#   * ``src/runtime/checkpointer_postgres.py`` — prod-only Postgres
+#     saver; CI runs sqlite-only.
+#   * ``src/runtime/triggers/transports/plugin.py`` — stub transport.
+#   * ``examples/**`` — reference apps; their MCP servers are exercised
+#     via integration tests under ``tests/`` but pytest's
+#     ``--cov=src/runtime`` does not instrument them, so coverage data
+#     never reaches SonarCloud for these files.
+#   * ``src/runtime/__init__.py`` — re-export surface only.
+sonar.coverage.exclusions=src/runtime/__init__.py,src/runtime/ui.py,src/runtime/__main__.py,src/runtime/checkpointer_postgres.py,src/runtime/triggers/transports/plugin.py,examples/**,ui/**
 
 # Suppress python:S7503 (async-without-await) for framework-driven async signatures.
 # LangGraph nodes and FastMCP tool handlers MUST be `async def` even when their
diff --git a/src/runtime/api.py b/src/runtime/api.py
index 0d3c11b..5bf8077 100644
--- a/src/runtime/api.py
+++ b/src/runtime/api.py
@@ -876,18 +876,19 @@ async def _stream():
                 last_seq = ev.seq
                 yield f"data: {envelope.model_dump_json()}\n\n"
             # Tail: poll for new rows. Bounded by client-disconnect.
-            try:
-                while not await request.is_disconnected():
-                    await _asyncio.sleep(0.25)
-                    for ev in event_log.iter_for(session_id, since=last_seq):
-                        envelope = EventEnvelope(
-                            seq=ev.seq, session_id=ev.session_id,
-                            kind=ev.kind, payload=ev.payload, ts=ev.ts,
-                        )
-                        last_seq = ev.seq
-                        yield f"data: {envelope.model_dump_json()}\n\n"
-            except _asyncio.CancelledError:
-                return
+            # CancelledError (from task cancellation, e.g. when the
+            # client closes the connection) propagates naturally — no
+            # try/except needed; suppressing it would break asyncio's
+            # cancellation contract (Sonar python:S7497).
+            while not await request.is_disconnected():
+                await _asyncio.sleep(0.25)
+                for ev in event_log.iter_for(session_id, since=last_seq):
+                    envelope = EventEnvelope(
+                        seq=ev.seq, session_id=ev.session_id,
+                        kind=ev.kind, payload=ev.payload, ts=ev.ts,
+                    )
+                    last_seq = ev.seq
+                    yield f"data: {envelope.model_dump_json()}\n\n"
 
         return StreamingResponse(_stream(), media_type="text/event-stream")