Fix refresh logic

[matyrr-havok]

Fix plan visualizer refresh reliability by making plan reads disk-first and making explicit refresh bypass stale cached state.

Changes

• Read plan.md directly from the session workspace before falling back to SDK plan RPC.
• Route toolbar/context-menu refresh through requestRefresh() instead of normal getState().
• Clear push dedupe state on explicit refresh.
• Only mark pushed state as delivered after webview eval succeeds, so reload/disconnect races can retry.

Testing

• node --check main.mjs
• node --check content\main.js