Display native Claude, Codex, Antigravity, and Grok subagents

[edwin-zvs]

Summary

• discover Claude Code Agent sidechains, Codex child rollouts, Antigravity child conversations, and Grok subagent updates from their native transcript stores
• project native children as persisted, read-only Construct sessions with live state and semantic transcripts
• render recursively nested native children in the TUI and web UI with explicit (native) labels
• prevent virtual children from daemon auto-resume and direct lifecycle management
• watch Grok updates.jsonl for subagent_spawned / subagent_finished instead of relying on chat_history.jsonl
• parse Antigravity INVOKE_SUBAGENT results and child SYSTEM_MESSAGE completion notifications
• document the ownership boundary in spec 0079

Verification

• cargo fmt --all -- --check
• cargo test --workspace (CLI socket tests rerun outside the restricted sandbox: 744 passed)
• cargo build
• adapter parser tests use the captured Antigravity and Grok lifecycle record shapes
• isolated-daemon after-only TUI recording verified at midpoint

Phase boundary

Codex child UUIDs are technically accepted by codex resume <SESSION_ID>, but this PR intentionally does not attach a second controller while the parent harness may still own the child. Claude Agent sidechain IDs are not accepted by claude --resume.

[edwin-zvs]

After-only TUI demo (isolated daemon with deterministic Claude/Codex native-child events):

[edwin-zvs]

Follow-up fix pushed in 1ad2de3:

• canonicalizes Claude child IDs so agent-<id> filenames and <id> lifecycle notifications resolve to one mirror
• publishes authoritative retained-child snapshots from the Claude watcher
• archives mirrors removed from Claude while preserving their transcripts
• unarchives a mirror if the native child reappears

Verification: focused identity/reconciliation tests pass, workspace test compilation passes, and cargo build passes. A full workspace run hit the existing timing-sensitive two_split_panes_same_session_reuses_cached_size_instead_of_thrashing test once; its immediate isolated rerun passed.

[edwin-zvs]

Confirmed root cause from the live isolated daemon: Claude writes both agent-<id>.jsonl and agent-<id>.meta.json; the watcher treated the metadata sidecar as a second transcript, creating <id> and <id>.meta mirrors. Commit 2c91a14 restricts discovery to agent-*.jsonl and adds a regression test. The authoritative snapshot then archives any already-persisted .meta mirror after the updated Claude adapter starts.