Plugin: handle stale binding conflicts after plugin reinstall or move

[huntharo]

Problem

If the plugin is uninstalled from one path and reinstalled from another, a previously bound conversation can get into a bad split-brain state:

• the plugin's local state says the conversation is not bound
• but OpenClaw core still rejects a new bind because the conversation is already bound

The user needs an explicit overwrite-or-cancel path when this happens.

Repro

1. Install the plugin from path A and bind a conversation.
2. Remove it.
3. Reinstall from path B.
4. Run /codex_status in the previously bound conversation.
5. The plugin may report "not bound", but binding again is rejected because core still has a binding record.

Current Findings

• The plugin only hydrates approved binds from its local pending-bind path; it does not have a true overwrite/conflict flow.
• The plugin SDK surface exposed here only gives us bind, unbind, and resolveByConversation for runtime conversation bindings.
• OpenClaw core/plugin binding tests explicitly show that persistent approvals do not carry across plugin roots even when pluginId stays the same.
• That makes plugin-move/reinstall behavior especially likely to surface as path/root identity drift.

Proposed Scope

• Detect when a conversation already has a runtime binding that conflicts with the plugin's local state.
• Distinguish "same plugin, new path/root" from unrelated binding ownership.
• Offer an explicit overwrite/detach/cancel prompt.
• Likely requires at least some OpenClaw core/API work so the plugin can inspect and replace the existing binding safely.

Source Notes

• Plugin bind request path: src/controller.ts:3044
• Plugin local binding storage: src/state.ts:147
• Plugin SDK runtime binding surface: src/openclaw-plugin-sdk.d.ts:158
• OpenClaw conversation runtime helpers: /Users/huntharo/github/openclaw/src/plugin-sdk/conversation-runtime.ts:1
• OpenClaw binding record helpers: /Users/huntharo/github/openclaw/src/bindings/records.ts:12
• OpenClaw test: persistent approvals do not carry across plugin roots: /Users/huntharo/github/openclaw/src/plugins/conversation-binding.test.ts:289