refactor: execute TinyJuice through its released bus module

.github/ci-paths-filter.yml

@@ -143,6 +143,8 @@ scripts:
   - '.github/workflows/ci-*.yml'
   - '.github/ci-paths-filter.yml'
   - 'scripts/ci/self-hosted/**'
+  - 'scripts/ci/check-module-boundaries.mjs'
+  - 'scripts/ci/module-boundaries.json'
   - 'scripts/mock-api/**'
   - 'scripts/*.mjs'
   - 'scripts/__tests__/**'

AGENTS.md

@@ -521,6 +521,8 @@ builds after changing a gate. Use `scripts/assert-shed.sh` or
 
 ## Loadable modules and bus contracts
 
+Hosts must interface with loadable components through their minimal `*-bus` contracts. Never import, re-export, link, or call their implementation libraries directly, including through wrapper crates or indirect dependencies. Execute component behavior through the compiled TinyBus module. If the required types or operations are missing, extend the contract and implementation in the owning repository and raise a PR against its canonical upstream first; then consume the released module and update OpenHuman’s gitlink and adapter. Do not introduce a host-side implementation workaround.
+
 ### Submodule ownership
 
 OpenHuman is the host and orchestrator for these components. It composes them,
@@ -601,7 +603,8 @@ Rules:
 - Never redeclare a contract type in OpenHuman.
 - Call members through contract constants, not string literals.
 - Contract crates stay synchronous and free of I/O and runtime dependencies.
-- Shared wire behavior belongs in the contract. Runtime, config, and security
+- Shared wire vocabulary belongs in the contract. Component algorithms execute
+  in the compiled module. Runtime, config, and security
   policy stay in the host.
 - Test the handwritten registry metadata against each contract's bus name and
   object path.