docs: clarify generic continuity adapter paths

plugins/continuity/HOOK.md

@@ -1,20 +1,37 @@
 # HOOK.md
 
-This document reserves the hook adapter contract for the continuity plugin MVP.
+This document defines the hook/host adapter boundary for the continuity plugin.
 
-## Target adapter
+## Target adapters
 
-Primary MVP integration target:
+Current supported adapter paths:
 
 - `force-recall`
+- `generic-preflight`
 
-## Planned responsibilities
+`force-recall` is the current primary OpenClaw integration path, but it is not the only intended host.
 
-- derive continuity input from hook context
-- invoke the plugin evaluator
+## Adapter responsibilities
+
+Adapters should:
+
+- derive or normalize continuity input from host context
+- invoke the shared continuity evaluator/engine
 - return a prompt block / gate result without duplicating continuity rules
+- keep host-specific parsing outside the core evaluator
+
+## Contract boundary
+
+The host-facing contract lives in the plugin engine and adapter exports:
+
+- `normalizeContinuityEngineInput()`
+- `createContinuityEngineContract()`
+- `runForceRecallContinuityAdapter()`
+- `runGenericPreflightContinuityAdapter()`
+- `runManualContinuityPreflight()`
 
 ## Current status
 
-- contract placeholder only
-- implementation deferred to later plan tasks
+- `force-recall` adapter: implemented and parity-oriented
+- `generic-preflight` adapter: implemented for host-agnostic/manual preflight integration
+- full installer/registry integration: intentionally out of scope for this package