[jacktrnr]

Closes #121.

What this does

A personal lane sends one researcher picks ranked against their own vault, as Slack DMs, alongside the shared channel digest.

[lanes.jackson]
recipient = "U0BC5EPT4HK"         # Slack member id — the DM target and the lane's only keeper
roots = ["~/vaults/jacktrnr"]     # never inherited from [vault]
feeds = ["math.AP", "quant-ph"]   # never inherited, never defaulted
top = 5                           # optional
papers_dir = "…"                  # optional; where the lane's keeps land

• arjev digest --lane <name> --post slack: opens the recipient's DM (conversations.open) before ranking, then posts a header ("arJev picks for you") plus one message per pick. The content boundary is the same as the channel's.
• arjev slack sync --lane <name>: harvests reactions and replies from the lane's DM. Only the recipient's reactions count, and keeps scaffold into the lane's own papers dir.
• State isolation: a lane_scope context variable routes state_dir() and ledger_path() to <state>/arjev/lanes/<name>/. Journal, posted ids, receipts and the ledger are all per-lane, and the persisted schemas are unchanged (invariant 8).
• arjev inspect prints one lane <name> <key>: <value> block per lane (recipient, roots, feeds, top, identity-bearing, directives). It blocks with blocked: lane <name>: no {recipient|roots|feeds} configured, or when the lane has zero identity-bearing notes.
• arjev daily runs every lane after the shared day: the digest is retried like the shared one, then the lane sync. A failing lane never stops the others. Lanes are skipped (and logged) when no Slack token is available.
• keep and staged also take --lane.
• The manifest and docs gain im:write and im:history. Existing app: add the two scopes and reinstall to the workspace (the token stays the same).

Acceptance criteria (#121)

• No-lane config is unchanged (ranking-parity test: fingerprint and scores identical).
• Lane picks arrive by DM, one message per pick, each with who-line and why-line.
• DM reactions label only that lane, and only from its recipient. Shared-channel reactions never label a lane (cross_lane_labels == 0, tested both directions).
• A lane ranks only its own roots (it never inherits [vault].roots).
• Per-lane posted-id and journal state (a paper the shared channel posted can still be picked in a lane).
• inspect reports each lane and blocks an empty-feeds lane, naming it.
• Manifest and setup docs carry the DM scopes, each mapped to its surface.

Tests

tests/test_lanes.py (21 tests, recorded Slack transport, no network). Full suite and ruff check . are green, with one exception: test_init_template::test_no_lab_name_anywhere_in_the_template fails locally only because my clone lives under ~/harmoniqs/, so the fixture-vault path written into the template contains "harmoniqs". It passes from a neutral path, and CI is unaffected.

Not in this PR

• review and calibrate stay shared-only. A per-lane week-in-review is a follow-up if wanted.
• No version bump. Left for the release.
• Companion: feat(ingest): cited-by-me seed — stage the works a researcher's own papers cite #122 (cited-by-me seed), a separate PR.