docs: move plugin roadmap out of docs/design and drop plan draft

README.md

@@ -1013,7 +1013,7 @@ PicoClaw provides typed lifecycle hooks for observability, outbound filtering, a
 
 See runnable examples: [docs/hooks-plugin-examples.md](docs/hooks-plugin-examples.md)
 
-Roadmap for plugin system evolution: [docs/design/plugin-system-roadmap.md](docs/design/plugin-system-roadmap.md)
+Roadmap for plugin system evolution: [docs/plugin-system-roadmap.md](docs/plugin-system-roadmap.md)
 
 <details>
 <summary><b>Zhipu</b></summary>

docs/design/plugin-code-plan-demo.md

@@ -1,71 +0,0 @@
-# Plugin System Demo Code Plan
-
-## Goal
-Build a minimal, executable demo to prove plugin value with measurable behavior (not conceptual discussion).
-
-## Why this demo
-This demo validates runtime capabilities that skill text cannot reliably enforce:
-- deterministic tool-call blocking at runtime
-- deterministic outbound content rewrite at runtime
-- reversible behavior (no plugin config => no effect)
-
-## Scope (1-day demo)
-In scope:
-- add one compile-time plugin: `policy-demo`
-- add tests for:
-  - global tool block
-  - channel-specific tool allowlist
-  - outbound redaction
-  - outbound deny-pattern guard
-  - tool argument normalization (timeout clamp)
-  - hook-based audit counters
-  - no-config no-effect path
-- provide a reviewer-friendly verification command
-
-Out of scope:
-- dynamic plugin loading
-- plugin marketplace/distribution
-- UI/config schema work
-
-## Code Changes
-1. `pkg/plugin/demoplugin/policy_demo.go`
-- add `PolicyDemoPlugin`
-- register `before_tool_call` hook to block configured tools
-- support channel-specific tool allowlist
-- normalize timeout-like tool args (`timeout`, `timeout_seconds`)
-- register `message_sending` hook for redaction and deny-pattern guard
-- register `session_start`, `session_end`, `after_tool_call` audit hooks
-- expose `Snapshot()` for deterministic verification
-
-2. `pkg/plugin/demoplugin/policy_demo_test.go`
-- `TestPolicyDemoPluginBlocksConfiguredTool`
-- `TestPolicyDemoPluginRedactsOutboundContent`
-- `TestPolicyDemoPluginChannelAllowlist`
-- `TestPolicyDemoPluginOutboundGuard`
-- `TestPolicyDemoPluginNormalizesTimeoutArg`
-- `TestPolicyDemoPluginAuditHooks`
-- `TestPolicyDemoPluginNoConfigNoEffect`
-
-## Verification
-Run:
-
-```bash
-go test ./pkg/plugin/... ./pkg/agent/...
-```
-
-Expected:
-- all tests pass
-- plugin test suite demonstrates deterministic runtime interception and rewrite
-
-## Acceptance Criteria
-- plugin can enforce a hard runtime policy (`before_tool_call` cancel)
-- plugin can enforce channel-level runtime policy without core code changes
-- plugin can enforce outbound transformation (`message_sending` rewrite)
-- plugin can enforce outbound hard-block (`message_sending` cancel)
-- plugin can mutate tool args before execution in a deterministic way
-- plugin can collect lifecycle audit counters
-- empty plugin config causes zero behavior change
-- behavior is covered by automated tests
-
-## Reviewer Notes
-If this demo is accepted, next step is wiring a config-driven enable/disable path (Roadmap Phase 2), while keeping current compile-time contract (`pkg/plugin`) unchanged.

docs/hooks-plugin-examples.md

@@ -2,7 +2,7 @@
 
 This guide shows how to extend PicoClaw behavior with `pkg/hooks` without modifying core agent logic.
 
-For future direction (beyond current hooks foundation), see [Plugin System Roadmap](design/plugin-system-roadmap.md).
+For future direction (beyond current hooks foundation), see [Plugin System Roadmap](plugin-system-roadmap.md).
 
 Current model:
 - "Plugin-style" means registering Go handlers at startup.