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/web-app/cordis.patch.yml

@@ -45,9 +45,6 @@
 # `dshClient` rows are the browser roster the modules node half scans into
 # window.__DSH_BOOT__; the modules row is simultaneously a host row.
 - insert:
-    - id: session-projection
-      name: '@deepseek-ai/dsh-session-projection'
-
     - id: code-runtime
       name: '@deepseek-ai/dsh-code-runtime-worker'