feat(web): mount llm-retry in the shipped web composition

The web tree had no transient-failure recovery around the loop's model
calls; the TUI agent-spine composition already mounts llm-retry. Same
defaults (2 retries, 500ms->10s backoff). The browser e2e retry scenario
drives it end-to-end: an injected SERVER throw at call 0 recovers through
the durable llm/retry record and completes in the transcript.

pnpm-lock.yaml

@@ -179,6 +179,9 @@ importers:
       '@deepseek-ai/dsh-llm-deepseek':
         specifier: workspace:^
         version: link:../../packages/llm/llm-deepseek
+      '@deepseek-ai/dsh-llm-retry':
+        specifier: workspace:^
+        version: link:../../packages/llm/llm-retry
       '@deepseek-ai/dsh-paths':
         specifier: workspace:^
         version: link:../../packages/util/paths