fix: address review round two

- listChildren contains per-child projection faults on both ladder rungs
  (any registered unit's fold/schema rejection maps to that child's corrupt
  diagnostic) and pins the whole-enumeration listing-failure rethrow
- the base bundle mounts session-projection (web-app's own insert retired
  to avoid the double mount); stale composition comment updated
- the shared projections-unavailable wire face is pinned across
  list/history/prompt; retired session-query arms removed from the catalog
  paths
- the design note records the unknown-parent semantics shift and the
  fold-fault isolation rule

packages/bundle/base/cordis.patch.yml

@@ -100,6 +100,12 @@
         path: ':memory:'
         openAt: first-search
 
+    # Shared projection registry: subagent catalog identity (mode/label) folds
+    # through its registered units, so the `list_agents` surface below fails
+    # loud without it; web layers reuse this same mount for list rows.
+    - id: session-projection
+      name: '@deepseek-ai/dsh-session-projection'
+
     # Session telemetry, on for every dsh mode: 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

packages/bundle/base/package.json

@@ -61,6 +61,7 @@
     "@deepseek-ai/dsh-session": "workspace:^",
     "@deepseek-ai/dsh-session-checkpoint-policy": "workspace:^",
     "@deepseek-ai/dsh-session-persistence-jsonl": "workspace:^",
+    "@deepseek-ai/dsh-session-projection": "workspace:^",
     "@deepseek-ai/dsh-session-query-sqlite": "workspace:^",
     "@deepseek-ai/dsh-session-telemetry-otel": "workspace:^",
     "@deepseek-ai/dsh-session-title": "workspace:^",