feat(selfhost): trace review pipeline in Sentry

.env.example

@@ -238,13 +238,13 @@ REDIS_URL=redis://redis:6379                # REQUIRED for the self-host review
 # --- Sentry error tracking (optional) ---
 # SENTRY_DSN=                                # enables self-host Sentry capture; unset = complete no-op
 # SENTRY_ENVIRONMENT=production
-# SENTRY_TRACES_SAMPLE_RATE=0                # traces/spans are off by default; errors still report. Set a LOW rate
-#                                            #   (e.g. 0.05) with SENTRY_DSN to sample review tracing: each sampled
-#                                            #   review emits a connected trace — the queue-job span (whole-review
-#                                            #   latency) with the AI-provider span nested — so you can filter slow
-#                                            #   or failed STAGES in Sentry without reading scattered logs. Spans
-#                                            #   carry only safe dimensions (repo, job type, provider/model); never
-#                                            #   prompts, diffs, tokens, or bodies. Leave 0 to keep tracing a no-op.
+# SENTRY_TRACES_SAMPLE_RATE=                 # traces/spans are off when blank/unset; errors still report. Set a LOW
+#                                            #   rate (e.g. 0.05) with SENTRY_DSN to sample review tracing: each
+#                                            #   sampled review emits a connected trace — the queue-job span
+#                                            #   (whole-review latency) with the AI-provider span nested — so you can
+#                                            #   filter slow or failed STAGES in Sentry without reading scattered logs.
+#                                            #   Spans carry only safe dimensions (repo, job type, provider/model);
+#                                            #   never prompts, diffs, tokens, or bodies.
 # SENTRY_RELEASE=                            # custom images only: set this ONLY when you uploaded source maps for
 #                                            #   the exact built bundle under this exact release id. Future official
 #                                            #   images bake GITTENSORY_VERSION=gittensory-selfhost@<version>, so do
@@ -271,7 +271,7 @@ REDIS_URL=redis://redis:6379                # REQUIRED for the self-host review
 # SENTRY_SERVER_NAME=                       # clean name for THIS instance in Sentry (e.g. gittensory-us-east);
 #                                           #   unset defaults to the OS hostname — never the public-origin URL
 # SENTRY_RELEASE=
-# SENTRY_TRACES_SAMPLE_RATE=0
+# SENTRY_TRACES_SAMPLE_RATE=
 
 # --- AI review backend (optional; without AI_PROVIDER reviews run deterministically) ---
 # AI_SUMMARIES_ENABLED=true

apps/gittensory-ui/src/routes/docs.self-hosting-operations.tsx

@@ -85,6 +85,13 @@ review_context_fetch_failed`}
       </p>
       <CodeBlock lang="bash" code={`docker compose --profile observability up -d`} />
 
+      <h2>Sentry tracing</h2>
+      <p>
+        Leave <code>SENTRY_TRACES_SAMPLE_RATE</code> unset or blank to disable trace export, or set
+        a positive sample rate such as <code>0.05</code> to send sampled review spans to Sentry. The
+        custom OpenTelemetry provider installs Sentry hooks for review-stage spans carrying repo,
+        PR, operation, outcome, and hashed installation tags.
+      </p>
       <h2>Sentry cron monitors</h2>
       <p>
         When <code>SENTRY_DSN</code> is set, the self-host runtime emits Sentry monitor check-ins

package.json

@@ -77,6 +77,7 @@
     "@opentelemetry/resources": "^2.8.0",
     "@opentelemetry/sdk-trace-node": "^2.8.0",
     "@sentry/node": "^10.62.0",
+    "@sentry/opentelemetry": "^10.62.0",
     "agents": "^0.16.2",
     "drizzle-orm": "^0.45.2",
     "hono": "^4.12.26",