Merge branch 'codex/simp-agent-entry-state' into codex/simp-unify-agent-session-id

# Conflicts:
#	docs/config-catalog.md
#	docs/cordis-catalog/services.md
#	docs/event-producer-consumer.md
#	docs/rfc/implemented/architecture/2026-06-18-agent-lifecycle-and-ownership-seams.md
#	docs/rfc/implemented/architecture/2026-06-20-branded-ids.md
#	docs/rfc/implemented/simplification/2026-06-20-remove-agent-boundary-mirror-events.md
#	docs/rfc/proposed/feature/2026-07-07-claude-code-and-codex-subagent-backends.md
#	docs/rfc/proposed/simplification/2026-06-20-unify-agent-and-session-id.md
#	packages/bash/tool-bash/README.md
#	packages/bash/tool-bash/src/index.ts
#	packages/bash/tool-bash/tests/tools.spec.ts
#	packages/core/agent-loop/README.md
#	packages/core/agent-loop/tests/properties.spec.ts
#	packages/core/agent/README.md
#	packages/core/agent/src/index.ts
#	packages/guard/repeat-tool-guard/src/index.ts
#	packages/hooks/hooks-claude/tests/bridge.spec.ts
#	packages/subagent/subagent-acp/tests/mock-acp-server.ts
#	packages/ui/acp/tests/dispose.spec.ts
#	packages/ui/stdio-agent/src/index.ts
#	packages/ui/stdio-agent/src/stdio-chat.ts
#	packages/ui/stdio-agent/tests/stdio-chat.spec.ts
#	packages/util/brand/src/index.ts

packages/core/agent-core/README.md

@@ -2,7 +2,7 @@
 
 The **default executor-less, UI-less agent spine** as ONE Cordis bundle plugin. It loads the fixed set of services every harness agent needs, including the local skill provider, and forwards the loop's `agents` list as its own config — so an app package composes a working agent by adding only a front door and the swappable backends.
 
-This is the package to read to see **the whole shared plugin tree at once**: the teaching overview of the spine behind every app package.
+Read this package for the whole plugin tree and its composition order.
 
 ## The tree it loads
 
@@ -47,7 +47,7 @@ The bundle FORWARDS each field to the child that owns it: `agents` to `agent-loo
 
 ## Why a code bundle, not a shared YAML include
 
-A YAML include can dedupe the config, but it cannot OWN a `bin`, and it can only *describe* the front-door coupling in a comment and trust each leaf to obey. Moving the spine into a package, and the front-door cluster into the app packages, means the default leaf for an ACP server has no logger entry to copy wrong — "the ACP app never logs to stdout" stops being a prose warning a leaf must remember and becomes the app package's default shape (a leaf can still add a sibling logger, so the rule stays documented — but it has nothing to get wrong by default). Services register in the root store keyed by their isolate symbol, so a child loaded here is visible to the bundle's siblings (the leaf's adapter and executor) exactly as a nested `plugin-include` subtree's services were — cordis gates every read on `inject`, never on load order.
+A YAML include can deduplicate config but cannot own a bin or provide front-door defaults. App packages make stdout-safe ACP wiring the default, though a leaf can still add an unsafe logger. Bundle children register services in the root isolate-keyed store, so injected leaf siblings see them without load-order coupling.
 
 ## Model Experience
 
@@ -55,6 +55,5 @@ Indirectly, through `dsh-system-prompt`, `dsh-tool-skill`, `dsh-tool-bash`, and
 
 ## Known Limitations and Deferred Work
 
-- **FIXME: package name and location imply product core** — rename `dsh-agent-core` to `dsh-demo-bundle` and move it under `packages/support/`; it is a demo composition bundle, not the product spine.
 - **The spine set is fixed in code** — `apply()` mounts every child unconditionally (including `tool-bash`); no config excludes or replaces one, so swapping the loop or dropping a spine member means composing a different bundle.
 - **`dsh-invariants` mounts unconditionally** — this bundle has no toggle, so every composition using it pays the dev-mode relational assertions; Session's always-on validation and freezing are separate.