♻️ Move semantic conversation parsing to the server

[Robdel12]

Summary

• move wrapper-style conversation parsing into a server-owned semantic materialization layer and add typed timeline rows for context, notices, shell commands, and task notifications
• materialize passive Codex worker, plan, hook, handoff, question, and approval events, and log unmatched wrapper-like messages for parser observability
• follow through on the Swift side by removing the old client-side conversation runtime and XML parsing helpers, moving worker detail rendering onto typed server conversation rows, and trimming unused conversation view surface area

Testing

• make rust-check
• make rust-test
• make rust-ci
• make test-unit
• xcodebuild -project OrbitDockNative/OrbitDock.xcodeproj -scheme OrbitDock -destination "platform=macOS" -derivedDataPath /tmp/orbitdock-derived build # compiles; later codesign failure on XCTAutomationSupport.framework appears unrelated

Notes

• make test-unit passes on the latest branch head (e2853e86)
• the Swift test run still prints pre-existing Swift 6 actor-isolation warnings in unrelated files, but they do not block the pass