feat(import): show imported sessions in entire session list

[computermode]

https://entire.io/gh/entireio/cli/trails/813

What

Makes sessions brought in by entire import appear in entire session list. Today import writes only read-only, commit-less checkpoints, so checkpoint list shows imported work but session list returns "No sessions." — the gap behind #1697 (and the read-only-import request in #1336).

Now each imported session also gets a local session.State, tagged Kind: imported, and is clearly marked read-only wherever it surfaces.

How

• entire import writes one session.State per imported session (agentimport.writeSessionState): reuses the transcript SessionID, aggregates real transcript timestamps + tokens, sets Phase: ended.
• Staleness: State.IsStale() exempts KindImported (historical timestamps would otherwise auto-purge imports on the first session list).
• Lifecycle purge paths gated on KindImported so a commit-less, shadow-branch-less imported state isn't deleted: listAllSessionStates orphan cleanup and ListOrphanedSessionStates (entire clean).

Read-only UX (so unsupported writes don't look like breakage)

Imported sessions are read-only — not resumable or rewindable. This is now surfaced instead of failing silently or cryptically:

• session list card shows imported (read-only)
• session info text adds a read-only note; session info --json and session list --json expose kind + read_only
• resume picker excludes imported sessions and, when the only sessions present are imports, explains why
• rewind already refuses imported checkpoints with a clear message (refuseIfImportedCheckpoint)

Forward-compat

Imported checkpoints are still local-only and not yet linked to commits or shown in the web UI. This PR is deliberately constrained so that a future change which links imports to commit SHAs (and pushes them for web-UI visibility) is purely additive:

• reuse the transcript SessionID as the join key
• gate capability on Kind, never on commit-presence
• never set BaseCommit (no HEAD pin, unlike entire attach)
• preserve real transcript timestamps (staleness handled via the Kind exemption, not faked recency)
• untouched: the entire/imports/v1 ref and push semantics — this PR writes only local .git/entire-sessions/*.json

Out of scope (intentionally)

Pushing imports / web-UI visibility, commit-SHA capture from transcripts (no importer parses one today), entire attach behavior, making imports rewindable.

Tests

• IsStale imported exemption (+ control)
• writeSessionState: field mapping, no-clobber of a live session, 30-day-old import survives strategy.ListSessionStates
• Run wiring: writes state on real import, skips on --dry-run
• lifecycle guards: listAllSessionStates keeps imported; ListOrphanedSessionStates skips imported
• read-only UX: list card, info text + JSON, resume picker exclusion + count helper

Full suite green (mise run lint + mise run test).

Refs #1697, #1336

🤖 Generated with Claude Code

[Copilot]

Pull request overview

This PR makes sessions imported via entire import visible in entire session list by writing a local session.State for each imported transcript and ensuring imported states aren’t removed by existing staleness/orphan-cleanup paths.

Changes:

• Write session.State entries for imported transcripts (Kind: imported, Phase: ended) so they appear in session listing.
• Exempt imported sessions from staleness deletion and from orphan cleanup/cleaner discovery.
• Exclude imported sessions from the resume picker (imports remain read-only).

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
cmd/entire/cli/strategy/manual_commit_session.go	Keeps imported session states during shadow-branch orphan cleanup.
cmd/entire/cli/strategy/manual_commit_session_test.go	Adds regression test ensuring imported states are not purged by listing cleanup.
cmd/entire/cli/strategy/cleanup.go	Prevents imported sessions from being offered as orphaned cleanup items.
cmd/entire/cli/strategy/cleanup_imported_test.go	Adds test confirming imported sessions are skipped by orphan cleanup listing.
cmd/entire/cli/session/state.go	Exempts imported sessions from IsStale() auto-purge behavior.
cmd/entire/cli/session/state_test.go	Tests IsStale() behavior for imported vs non-imported sessions.
cmd/entire/cli/resume_picker.go	Filters imported sessions out of the resumable-session picker.
cmd/entire/cli/resume_picker_test.go	Tests that imported sessions are excluded from resumable sessions.
cmd/entire/cli/agentimport/agentimport.go	Writes imported session.State best-effort after importing checkpoints; adds token aggregation + state writer.
cmd/entire/cli/agentimport/session_state_test.go	Adds unit tests for imported session state creation and Run wiring (including --dry-run).