refactor(instance): remove remaining bind call sites

[nexxeln]

summary

• centralize instance/workspace callback restoration in EffectBridge.bind
• migrate file watcher, workflow approval, and database callbacks off InstanceState.bind
• keep callback owners simple while preserving sync watcher/DB behavior and async approval flow

testing

• bun typecheck
• bun test "test/session/llm.test.ts"
• bun test "test/storage/db.test.ts" "test/sync/index.test.ts"
• bun test "test/file/watcher.test.ts" (5 watcher cases pass; the symlinked .git case times out locally, and the same timeout reproduces with the original callback restored on dev)