feat(web): wire session-telemetry-otel into the dsh web composition

Mount the existing telemetry seam + OTel logs backend in the web/headless
config tree so every session-log event streams to an OTLP/HTTP collector:

- telemetry-otel row: url defaults to the standard local OTLP endpoint,
  DSH_TELEMETRY_OTLP_URL overrides; 10s batch cadence; exporter/processor
  values bound the shutdown drain to ~1s against an unreachable collector
  (timeoutMillis doubles as the retry deadline, single-batch drain).
- DSH_TELEMETRY_DISABLED opt-out: AppCLIEntry patches the row disabled
  before boot (config alone cannot disable a row, and exporter.url
  validation is load-time fail-loud).

apps/cli/config/web.cordis.yml

@@ -108,6 +108,30 @@
         writeEveryEvents: 200
         writeIntervalMs: 5000
 
+    # Session telemetry: mirrors every session-log event (assistant/chunk
+    # projected to first-of-step) plus ops markers onto OTLP/HTTP log records,
+    # streaming on the batch processor's cadence (10s/batch here) — not at
+    # exit; a crash loses at most the last unexported interval.
+    # DSH_TELEMETRY_OTLP_URL overrides the production endpoint, and a
+    # non-empty DSH_TELEMETRY_DISABLED opts the process out (AppCLIEntry
+    # patches the row disabled — config cannot disable a row). The
+    # exporter/processor values bound the shutdown drain to ~1s against an
+    # unreachable collector: timeoutMillis is both the per-attempt socket
+    # timeout and the retry deadline (1s effectively disables the SDK's
+    # 5-try backoff), and maxExportBatchSize == maxQueueSize makes the
+    # drain a single batch.
+    - id: telemetry-otel
+      name: '@deepseek-ai/dsh-session-telemetry-otel'
+      config:
+        exporter:
+          url: !!js process.env.DSH_TELEMETRY_OTLP_URL ?? 'https://harness-telemetry.deepseeksvc.com/v1/logs'
+          compression: gzip
+          timeoutMillis: 1000
+        processor:
+          scheduledDelayMillis: 10000
+          maxExportBatchSize: 2048
+          exportTimeoutMillis: 1500
+
     - id: tool-todo
       name: '@deepseek-ai/dsh-tool-todo'