perf(cli): stabilize subagent inspection and dispatch portability - #2007

Summary

• Keep the existing OpenCode-aligned View subagents entrypoint while moving lineage query/inspection work off the TUI render loop, adding per-session freshness fences and bounded refresh backoff.
• Make the Runtime the authoritative owner of settled-turn validation, transcript construction, exact-turn cancellation admission, and terminal persistence; the TUI no longer maintains a parallel settlement state machine or text heuristics.
• Upgrade private shared Runtime IPC to protocol v15 with a dedicated reader, one ordered writer, and supersedable speculative lineage reads so cancellation is not queued behind inspection.
• Include the confirmed Windows Dispatch portability fixes: inject the existing runner boundary in tests instead of spawning an unsupported detached process, persist non-verbatim checkout paths, and compare Git paths/line endings semantically.

Architecture and behavior

• Reuses the existing Agent Runtime, CoreSessionOperationsPort, coordinator mutation lease, session persistence, and TUI event projection. No second Runtime, transcript cache, generic request multiplexer, or new user command is introduced.
• The outer subagent execution task is the sole terminal persistence owner. Descendant cancellation signals its token and lets that owner drain engine/tool work and write one terminal outcome.
• Cancellation checks the exact active Turn under the session mutation lease. Once admitted, failures are returned as typed OutcomeUnknown rather than implying a safe retry.
• Runtime inspection accepts bounded settled-Turn preconditions and returns an authoritative transcript only after every required terminal Turn is durable.
• TUI fallback state remains bounded to 1 MiB / 4096 events and 256 settled-Turn barriers; event freshness is tracked per session.
• IPC v15 intentionally fails closed against older private daemons through the existing protocol-version handshake.

Performance and consistency evidence

Non-goals

• No Relay feature work.
• No Windows detached Dispatch runner implementation.
• No generic IPC multiplexing framework, new Runtime/cache, pagination layer, notification center, or invented TUI/slash command.
• No workflow changes and no Superpowers documents.

Validation

• cargo test --workspace -j 2 --quiet -- --format terse
• cargo check --workspace -j 2
• cargo test -p bitfun-cli -j 2 (653 unit tests plus all CLI integration suites)
• cargo test -p bitfun-services-integrations --all-features -j 2 (474 unit tests plus contract/doc tests)
• cargo test -p bitfun-services-integrations --features review-platform repository_root_accepts_nested_and_file_paths -- --nocapture
• cargo test -p bitfun-agent-runtime-ipc -j 2 (61 tests)
• cargo test -p bitfun-agent-runtime lineage -j 2
• cargo test -p bitfun-core lineage -j 2
• cargo test -p bitfun-core post_admission -j 2 -- --nocapture
• cargo test -p bitfun-runtime-ports session_lineage_contracts_serialize_provider_neutral_facts -j 2
• node scripts/check-core-boundaries.mjs
• Changed Rust files: rustfmt --edition 2021 --check; git diff --check

The local Windows workspace uses 16 logical cores with a small page file; an earlier unconstrained concurrent link run reproduced rustc exits with 0xc0000409 under commit pressure. The final workspace check and unfiltered workspace test use -j 2 to control linker concurrency, not to reduce test coverage. No CI/workflow workaround is included.