feat(observability): add OpenTelemetry request tracing

- Add opt-in OTLP/HTTP export with bounded background batching.
- Propagate W3C context and correlate wide events with response trace IDs.
- Update my_helpers for Convex child spans and native request IDs.
- Respect parent sampling and shut down the exporter off the event loop.
- Keep raw URLs, payloads and exception text out of spans.
- Cover worker isolation, retries, sampling, privacy and exporter lifecycle.
- Document collector configuration and bump NanoShare to 1.27.5.
- Refresh locked dependencies, including pytest and watchdog.
- Validate the changes with 293 passing tests.

my_modules/app/setup.py

@@ -12,6 +12,7 @@ from my_modules.filecache import build_file_cache
 from my_modules.app.logger import logger
 from quart_common.web.request import TRUST_PROXY_HEADERS, TRUSTED_PROXY_IPS, TRUSTED_PROXY_CIDRS
 from quart_common.web.wide_event import register_wide_event_logging
+from my_modules.observability import register_request_tracing
 
 from my_helpers.db.convex.ConvexRuntime import ConvexRuntime
 from my_helpers.db.convex.ConvexWorkerPool import ConvexWorkerPool
@@ -30,6 +31,7 @@ app = Quart(__name__,
 )
 app.config['MAX_CONTENT_LENGTH'] = 1024 * 1024 * 1024
 register_wide_event_logging(app, logger)
+register_request_tracing(app)
 
 app.secret_key = SECRET_KEY