Tasks: the mention is the address, and three acts each end in the session

Phase 4 of 4. Derived mechanically from the approved design.md and testing-plan.md; each task names the requirement it satisfies and the matrix row that proves it. No approval gate (issue-281). Test-first per task: a failing test motivates the code, and the commit message records the red→green command.

Tasks

[x] 1. Catalog rows, schema text, docs pins. channels/events.py gains context.added and decision.recorded (origin channel, publishable, recorded, not subscribable); both cli-config.schema.json copies' publish description, the channels options page's grant table and the shipped cli-config.yaml comment name them; test_bus.py's pinned sets grow by two. Req: R4.6, R5.5, R8.1 (design §8). Test: T1 (test_bus.py), T10 (test_docs_parity.py, test_config_schema_parity.py), test_the_docs_list_every_publishable_event.
[x] 2. Manifest and probe. slack-app-manifest.yaml gains app_mentions:read, the app_mention bot event and the two message shortcuts; the guide's fenced copy is byte-equal; subscription_findings measures app_mentions:read and names the consequence; the connect-time probe and channels status --probe report it. Req: R1.8, R6.1 (design §1, §6, §8). Test: T6 (test_channels_dm.py, test_channels_commands.py), T10.
[x] 3. channels/verbs.py. strip_mention, parse_verb, compose_keyword, help_text. Req: R3.1, R3.2, R3.4 (design §3). Test: T1 (test_channels_verbs.py).
[x] 4. Roster: a Slack id. CollaboratorRecord.slack, login optional when slack is set, fail-closed from_dict; parse_subjects (@login, slack:U…); slack_ids(), is_collaborator_slack(); add(login=, slack=); the dispatcher's _apply_collaborator and command_comment speak both; the CLI's --slack resolves a handle through the directory. Req: R3.5, R7.1, R7.4 (design §5). Test: T1 (test_collaborators.py), T2 (test_collaborators_cli.py), T8 A11, T10.
[x] 5. Room: the listen mode. CollaborationChannel.listen with the two-value guard; control._parse_channels reads --listen; store.add(listen=); the dispatcher's _apply_channel and the CLI's --listen; command_comment spells it back; ChannelStores.listen_mode; channels threads prints it. Req: R2.1, R2.3, R2.4 (design §2). Test: T1 (test_workchannels.py), T2 (test_workchannels_cli.py), T8 A12, T10.
[x] 6. Ledger record shapes. GitHubLedger.record mirrors context.added and decision.recorded as marked, quoted, scrubbed, defanged, enveloped comments whose visible line names the act and the person. Req: R4.1, R4.3, R5.1, R5.4 (design §4). Test: T1 (test_channels.py), T8 A5, A6.
[x] 7. Session frames. reply_session(kind=) with the context and decision frames composed from fixed words, the ref, counts and URLs, naming the text untrusted. Req: R3.7 (design §4). Test: T1 (test_channels_mentions.py), T8 A4.
[x] 8. Inbound: the address, the tiers, the verbs, the acts.handle_socket_event(addressed=) and the §1 input table (DM, all room, everything else) with the not-addressed and duplicate drops; speaker_for and the act table; _classify step zero; help ephemeral; record-context through SlackBotChannel.snapshot_thread (cap, links, names, scrub order, snapshots state under the lock, nothing-new answer, size refusal); record-decision (empty refusal, kind and rationale); _DELIVERED; the thread reply with the record's link; the kickoff by mention. Req: R1.1–R1.6, R1.9, R2.2, R3.1–R3.7, R4.1–R4.5, R5.1–R5.4, R7.2–R7.5 (design §1, §3, §4, §5). Test: T1, T2 (test_channels_mentions_integration.py), T8 A1–A10.
[x] 9. Listener routing, shortcuts, modal. handle routes app_mention, message_action, view_submission; handle_message_action and handle_view_submission; decision_view; views_open; post_ephemeral; once.py ring shared with the slash command. Req: R1.1, R6.1–R6.6 (design §1, §6). Test: T2 (test_channels_shortcuts_integration.py), T6 (test_channels_shortcuts.py), T8 A3.
[x] 10. the-loop channels records. A read-only verb listing a work item's enveloped context.added / decision.recorded records (url, actor, ts, body) as json or markdown. Req: R4.7, R5.6 (design §7). Test: T2 (test_channels_records_integration.py).
[x] 11. Status lines and the poll skip. channels status prints mentions:, shortcuts: and the all-room count; fetch_replies / fetch_channel_messages skip mention-gated conversations and move no cursor. Req: R1.7, R2.4, R6.6, R1.8 (design §1, §8). Test: T2, T6.
[x] 12. The operating model and the docs. templates/context.md; the workItemArtifacts row; interaction._ARTIFACT_RULE; SKILL.md, workflow.md, collaboration.md; docs/guide/slack.md (modes table, Addressing the-loop, the room, upgrade table, limits, downtime); docs/capabilities/channels.md and webhook-triggers.md with history rows; routing-options.md for --listen; evidence/documentation.md. Req: R4.7, R5.6, R8.2–R8.4 (design §7, §9). Test: T10 (test_graph_parity.py, test_interaction.py), T12.
[x] 13. Verification, reviews, evidence. Run the plan (T1, T2, T6, T8, T10, T12; T11 recorded as not executable here, no workspace), fill Verification results, write evidence/*.md, the self-review and critic-review records, the security review, the PR briefing. Req: all. Test: the plan's activities.

Notes

Tasks 1–7 are independent of each other; 8 depends on all of them; 9–11 on 8; 12 on the design alone; 13 last.
Every commit: <type>(issue-389): … with the test command and its red→green line.