refactor(core): move remote and shell execution owners

[limityan]

Summary

• Move remote-connect command routing and response assembly ownership into bitfun-services-integrations; core RemoteServer now delegates through host adapters.
• Move reusable Bash shell policies, command wrapping, noninteractive env, local/remote result rendering, and background-result text into tool-runtime::shell; core BashTool keeps terminal/session/checkpoint/cancellation/scheduler glue.
• Add focused owner tests and boundary rules, then update the active plan and completed-summary docs without changing stable architecture design docs.

Risk and behavior boundary

• No tool schema, permission semantics, terminal lifecycle, remote wire shape, or product capability exposure changes are intended.
• tool-runtime adds no new third-party dependencies and does not depend on bitfun-core, Tauri, provider clients, or platform-specific runtime APIs.
• Indexed workspace search service ownership, permission wait, checkpoint orchestration, and full tool pipeline migration remain in the next milestone and are documented as unfinished.

Verification

• cargo test -p tool-runtime
• cargo test -p bitfun-core bash_tool --features product-full
• cargo test -p bitfun-core remote_answer_question_preserves_user_input_manager_path --features product-full
• cargo test -p bitfun-services-integrations --features remote-connect remote_connect_command_owner --tests
• cargo check -p bitfun-core --features product-full
• cargo check -p bitfun-core --no-default-features
• node scripts/check-core-boundaries.mjs
• node --test scripts/check-core-boundaries.test.mjs
• pnpm run check:repo-hygiene
• cargo metadata --no-deps --format-version 1
• git diff --check