Line snapshots seal only admitted paths

[renmengye]

Follow-up to #442. A research-line snapshot publishes the agent's working tree to its line branch at the end of an attempt, and on a crash as salvage. #442 kept rejected trees off the normal ending paths, but an exception right after a scope refusal could still let salvage push a tree with out-of-scope changes. Separately, a run that ended normally with one stray file sealed that file onto the line.

What changes

• _push_line_snapshot (every caller: normal endings, salvage, wake and publish tails) seals only admitted paths: out-of-scope tracked changes are restored to their content in the snapshot's parent (or dropped if absent there), out-of-scope untracked files are left out, and everything admitted, including line memory, is sealed as before. One bounded log line names the dropped paths. Out-of-scope session commits also stay out of line history.
• The filtering uses a private index, so the working tree and the real index are untouched for whatever runs next.
• The line branch never receives an out-of-scope change, and the agent keeps its notes and admitted work instead of losing the whole snapshot.

Compatibility (RELEASING.md)

No persisted-state format change. Existing line branches are unchanged; only future snapshots filter. Rollback returns to sealing the full tree.

Tests

A normal ending with a stray untracked file seals admitted work and line memory without it (mutation-checked); a protected tracked file edited is sealed at its parent content; a crash right after a scope refusal leaves no out-of-scope change on the line; clean trees are unchanged. Gate: 2620 passed, 6 skipped; ruff, format, mypy clean.

Built by codex from my brief; my cross-review changed the first version (which skipped the whole snapshot and lost the run's notes) to filter instead.

🤖 Generated with Claude Code

[github-actions]

Round 1 — reviewed head 1d9526b3 — reviewer summarizer:hermes/gpt-5.6-terra over coverage+credentials+deployment+general+lifecycle+prose.

terra
Advisory findings from outerloop — the code owner decides. Reply to disagree; the outerloop:no-review label opts this PR out.

Verdict: no defects found.

No findings were reported by any review lens. Rejected findings: none.

[github-actions]

Round 1 — reviewed head 4aec883b — reviewer hermes/gpt-5.6-terra.

terra
Advisory findings from outerloop — the code owner decides. Reply to disagree; the outerloop:no-review label opts this PR out.

Verdict: no defects found.