merge: v0.5.3 SESSION-FOLD — orchestrator-session-host into orchestrator-plugin-host::session

- crates/orchestrator-session-host/src/*.rs → crates/orchestrator-plugin-host/src/session/ (5 files, ~2406 LOC)
- crates/orchestrator-session-host/tests/plugin_supervisor.rs → crates/orchestrator-plugin-host/tests/plugin_supervisor.rs
- plugin-host absorbs session-host's deps: animus-session-backend, orchestrator-logging, async-trait, uuid (with rt-multi-thread tokio feature)
- session/mod.rs re-exports session-host's old top-level surface; consumers now use orchestrator_plugin_host::session::... (no top-level plugin-host re-export — namespace boundary stays visible)
- 6 import sites updated across agent-runner, orchestrator-cli, orchestrator-daemon-runtime

Workspace: 13 → 12 crates (after CORE-FOLD's earlier 15 → 13).

Merge conflicts in CLAUDE.md / AGENTS.md / CONTRIBUTING.md / Cargo.toml / docs/architecture/{full-system-architecture,runtime-architecture}.md / docs/contributing/development.md resolved by keeping NEITHER side's stale entries (both CORE-FOLD and SESSION-FOLD dropped different crates from the same workspace lists). The session/ module + lib.rs registration + plugin-host Cargo.toml + tests/plugin_supervisor.rs were restored from the SESSION-FOLD branch after git's auto-resolve kept HEAD's pre-fold state.

Branch: worktree-agent-a6866552122972629 (commit 73338b8).

Author: Shooksie

AGENTS.md

@@ -45,8 +45,7 @@ crates/
 ├── orchestrator-daemon-runtime/ # Daemon queue and scheduling runtime
 ├── orchestrator-logging/        # Shared tracing and log file utilities
 ├── orchestrator-notifications/  # Notification/runtime integration support
-├── orchestrator-plugin-host/    # Plugin discovery, install, and stdio host
-├── orchestrator-session-host/   # Session backend layer + provider/plugin execution bridge
+├── orchestrator-plugin-host/    # Plugin discovery, install, stdio host, session backend bridge (folded in v0.5.3)
 └── protocol/                    # Shared protocol/config/runtime types
 ```
 

CLAUDE.md

@@ -38,7 +38,7 @@ Animus is a Rust-only agent orchestrator with:
 
 Do not reintroduce stale claims such as:
 
-- stale workspace-count summaries that do not match `Cargo.toml`'s current 13 members
+- stale workspace-count summaries that do not match `Cargo.toml`'s current 12 members
 - "plugin extraction in flux" or "in progress" framing — extraction is complete as of v0.4.12
 - `PROJECT_ROOT` or "last-project-root registry" resolution rules
 - removed crates like `llm-mcp-server`, `llm-cli-wrapper`, `orchestrator-web-api`, `orchestrator-web-contracts`, or in-tree `animus-provider-{claude,codex,gemini,opencode,oai}`. `orchestrator-web-server` still exists in-repo but is not a current workspace member
@@ -60,7 +60,6 @@ Runtime and provider layer:
 - `crates/agent-runner`
 - `crates/orchestrator-daemon-runtime`
 - `crates/orchestrator-notifications`
-- `crates/orchestrator-session-host`
 - `crates/orchestrator-logging`
 
 Plugin host + protocol:

CONTRIBUTING.md

@@ -55,8 +55,8 @@ cargo animus-lint
 The workspace is organized into functional crates:
 
 - **Core orchestration**: `orchestrator-cli`, `orchestrator-core` (includes the v0.5.3 folded-in `subject_adapter` and `store` modules), `orchestrator-config`
-- **Runtime & agents**: `agent-runner`, `animus-runtime-shared`, `orchestrator-daemon-runtime`, `orchestrator-session-host`
-- **Plugin host**: `orchestrator-plugin-host`, `animus-plugin-protocol`, `animus-plugin-runtime`
+- **Runtime & agents**: `agent-runner`, `animus-runtime-shared`, `orchestrator-daemon-runtime`
+- **Plugin host**: `orchestrator-plugin-host` (includes `session::*` folded in v0.5.3), `animus-plugin-protocol`, `animus-plugin-runtime`
 - **Utilities**: `orchestrator-notifications`, `protocol`
 - **Web stack**: shipped as external plugins (`launchapp-dev/animus-transport-http`, `animus-transport-graphql`, `animus-web-ui`). Install with `animus plugin install-defaults --include-transports`.