Retire channels/sessions/messages; A2A becomes primary agent comms (#306)

* feat(a2a): deliver latest incoming message preview into the claim briefing

list_unread_a2a now carries last_message_preview (the latest message from the
OTHER agent, never the agent's own reply), fetched via a correlated subquery in
the same query — no N+1 on the per-verb briefing path.

* feat(a2a): read_a2a verb delivers unread message bodies to the agent

A2AService.get_unread_messages returns the caller's unread INCOMING messages
(never its own sends), marking exactly those rows read atomically so a message
arriving mid-call is preserved. Wired as the read_a2a content verb (route +
do_server tool + granted to every delivery role) — the content-bearing read the
A2A inbox lacked (read_messages only zeroed the counter).

* docs(rag): document read_a2a as the A2A content-read path

* fix(task): backlog activation no longer requires a discussion session

Removes the SessionTaskTable gate in activate() (and its dangling log field),
deletes _inherit_parent_session + its create() call, and drops the now-unused
SessionTaskTable import. Coordination rides task state; the session subsystem is
being retired. Tests updated to the new (no-session) behavior.

* fix(orchestrator): drop session sweep from _run_sweep

Removes the messaging import + sweep_timed_out_sessions call. That import sat
outside the try/except, so once messaging.py is deleted it would have killed the
entire sweep cascade (budget kill-switch, token rollups, retention, image prune,
superseded-PR reconcile). Notification sweep + all maintenance sweeps unchanged.

* release-manager --no-tags read-clone fix

* test: update evidence_repo unit test for a2a last_message_preview

* refactor(gateway): drop session propagation on delegate

Removes propagate_sessions_to_subtask from delegate(), the ChoreographerDeps
messaging field + property, and the ChoreographerDeps messaging arg in deps.py
(ContentActions messaging + import stay until the verbs are removed). Deletes the
propagation test; strips the now-invalid messaging kwarg from ChoreographerDeps
test builders.

* refactor(gateway): remove say/open_session/link_session/channels verbs

Removes the four channel/session verbs across content_actions (impls +
ContentActionsDeps.messaging), do_server (tools + registry), role_config (grants
+ _CHANNEL_DISCOVERY), do.py (routes), schemas/v1/do.py (request models), and
deps.py (MessagingService import + construction). Regenerates the prompt verb
tables. dm/notify/read_messages/read_a2a stay. Tests deleted/updated accordingly.

* uv.lock Upgrade

* refactor: remove conversation RAG indexing; Secretary announces via notification

Drops the CONVERSATIONS index (index_conversation, ConversationsIndexPlugin,
IndexType.CONVERSATIONS enum, IndexConversationParams, mentor.py type-label, the
messaging index hook) and its chunk-table manifest entries. The Secretary's
ANNOUNCE/RELAY_MESSAGE now fan out a BROADCAST notification to every agent's
inbox (NotificationService.broadcast) instead of posting to a dead channel.

* fix(panel): label RAG health error lines by subsystem

A red llm_error (e.g. the glm-5.2:cloud weekly-limit 429) rendered under
the 'Embedding: ok' header with no label, reading as an embedding failure.
Prefix each error line with LLM / Embedding / Vector store.

* refactor: remove channel/message reads from metrics, dashboard, git, events

MetricsService drops get_communication_volume + the MessageTable
message-count in get_agent_metrics (and the now-dead messages_sent_week
field). DashboardService drops get_channel_feeds/_compute_channel_status
and the message read in get_recent_activity (task activity kept);
get_auditor_metrics no longer reports communication_volume.
GitService's two primary-session-id helpers always return None now
(callers already treat None as "no primary session"). events/handlers.py
drops the SESSION_CLOSED/SESSION_TIMEOUT subscriptions + the
handle_session_boundary handler.

Forced follow-on: api/routes/dashboard.py + api/schemas/dashboard.py
dropped the now-dangling live_feeds/ChannelFeed surface and the
/metrics/communication route, which wrapped the removed service calls
directly (mypy would otherwise fail on the missing attributes).

* refactor: delete MessagingService + channel seeding

Edited db/__init__.py and services/__init__.py first (drop the unconditional
Channel/Group/Message/Session table + MessagingService re-exports), then
deleted services/messaging.py, then trimmed db/seed.py to only create_agents
(create_channels/create_channel_memberships/create_initial_messages gone).

Forced expansion: api/routes/{channels,groups,sessions,messages}.py import
roboco.services.messaging directly (not through the package __init__), as
does api/routes/tasks.py (the session-links embed on GET /tasks/{id} and the
GET /{id}/sessions route). Deleting messaging.py without addressing these
breaks `import roboco.api.app` immediately, since app.py eagerly imports all
route modules at startup. Since the 4 CRUD route files are 100%
MessagingService-backed with zero independent logic (and are wholesale
deletes in the plan's later API-routes task anyway), deleted them now +
unmounted from app.py/routes/__init__.py; tasks.py got the same surgical
trim its later task already specified (drop session-links embed +
TaskSessionLinkResponse/TaskResponse.sessions). This pulls a slice of that
later work forward — the routes/schemas for channels/groups/sessions/messages
still need their own pass, but their messaging-coupled parts are gone.

Verified with a full-suite collection sweep (12010 tests collected, zero
import errors) beyond the directly touched test dirs, given the expanded
blast radius.

* refactor: remove channel/session/message models, tables, and channel policy

Models: deleted channel.py/group.py/session.py/messaging.py wholesale
(zero external consumers besides the models/__init__.py re-export).
message.py surgically trimmed: removed MessageCreate (dead) and MessageEdit
(never instantiated; ExtractedMessage.edit_history retyped to
list[dict[str, Any]] to match how it's actually persisted — confirmed
ExtractedMessage was never written to any DB table, so MessageTable's
removal carries no functional risk to the kept extraction pipeline).
base.py: removed SessionStatus + ChannelType, kept MessageType. Also
removed the confirmed-dead channels_read/channels_write fields from
models/agent.py:AgentPermissions and models/dashboard.py:ChannelFeedData.

db/tables.py: deleted ChannelTable/GroupTable/SessionTable/SessionTaskTable/
MessageTable, TaskTable.session_links, and JournalEntryTable.session_id —
cascaded through models/journal.py, services/journal.py, and
api/schemas+routes/journals.py (22 plumbing sites).

foundation/policy/communications.py: removed the ChannelSpec/CHANNELS
catalog + TEAM_SCOPED_ROLES/_CELL_*/_AUDITOR_ONLY helpers, kept the
notification policy (Priority/parse_priority/NOTIFY_SENDER_ROLES/
ACK_REQUIRED_BY_TYPE). enforcement/channel_access.py deleted (confirmed
fully dead in production). agents_config.py: removed CHANNEL_ACCESS
(kept A2A_ALLOWED_PAIRS). seeds/initial_data.py: removed
DEFAULT_CHANNELS/CHANNEL_MEMBERSHIPS/AUDITOR_SILENT_ACCESS + the
never-consumed INITIAL_MESSAGES. config.py: removed
session_idle_timeout_seconds (zero consumers). exceptions.py: removed
dead ChannelError/ChannelAccessDeniedError/SessionClosedError.

Forced expansion beyond the original file list — ChannelType cascaded
into a live, mounted surface the plan didn't trace: agents_config.
CHANNEL_ACCESS -> services/permissions.py's channel-RBAC methods (not
models/permissions.py, which turned out to have no channel code at all)
-> two real endpoints in api/routes/stream.py (GET /permissions,
GET /permissions/channel/{name}) and two dependency factories in
api/deps.py. Removed the channel methods + fields, deleted the
channel-specific stream.py endpoint, deleted require_channel_read/write.
Also deleted api/schemas/{channels,sessions}.py (hard dependency on the
removed enums; already fully dead after the Task 10 route deletions) and
api/schemas/messages.py (a TYPE_CHECKING-only import of the deleted
MessageTable; likewise already fully dead) + its dedicated test file.

Test updates: test_permissions.py -14 channel tests (matches the planned
count exactly), test_communications.py / test_communications_consumers.py
split to keep only notification-policy coverage, test_exceptions.py -9,
test_deps.py -4, plus the journal/stream/foundation-smoke fallout. Also
fixed a pre-existing (Task 7) broken assertion in
test_foundation_phase3_smoke.py that inspected a `say()` method already
removed from ContentActions.

Verified: full-suite collection (11961 tests, zero import errors) and a
complete test run (11567 passed, 394 skipped, 0 failed) in addition to
the targeted suites.

* migration: drop channels/groups/sessions/session_tasks/messages + enum types

alembic/versions/060_drop_messaging.py: drop_column journal_entries.
session_id (sidesteps hardcoding the FK constraint name — verified
empirically against a live migrated DB that it's actually
fk_journal_entries_session_id_sessions, but drop_column doesn't care
either way); drop_table in FK order (messages -> session_tasks ->
sessions -> groups -> channels); DROP TABLE IF EXISTS chunks_conversations
(runtime-provisioned, not alembic-managed, would otherwise orphan); DROP
TYPE IF EXISTS for messagetype/sessionstatus/sessionscope/channeltype
(messagetype's Python enum stays for ExtractedMessage, but the DB type
had zero live columns left once MessageTable was dropped in the prior
commit). downgrade() raises NotImplementedError — one-way removal.

Pruned scripts/reset_runtime_state.sql + .sh: removed the DELETE/COUNT
lines for messages/session_tasks/sessions/groups/channels and the
groups.active_session_id reset block.

Verified end-to-end against a scratch Postgres DB: full migration chain
001->060 applies cleanly, alembic heads shows a single head, all 6 dropped
tables + 4 enum types + the journal_entries.session_id column are
confirmed gone, journal_entries keeps only its journal_id/task_id FKs,
downgrade correctly raises NotImplementedError without corrupting DB
state, and the pruned reset_runtime_state.sql runs clean (no errors)
against a fully-migrated DB.

* refactor(api): remove channel/session/message routes + WS streams

Most of this task's file list was already forced through in earlier
commits (routes/{channels,groups,sessions,messages}.py + app.py/__init__.py
unmounting in the MessagingService-deletion commit; tasks.py's
session-links embed + GET /{id}/sessions + schemas/tasks.py's
TaskResponse.sessions in that same commit; deps.py's require_channel_read/
write + schemas/{channels,sessions}.py in the models/tables commit). This
closes out what was left:

- api/websocket.py: deleted the channel_stream + session_stream routes,
  ConnectionManager's channel_connections/session_connections dicts,
  connect_channel/connect_session, broadcast_to_channel/broadcast_to_session,
  get_channel_subscriber_count, and their cleanup lines in disconnect().
  Agent streams, notification streams, and the operator system stream are
  untouched.
- api/websocket_bridge.py: deleted _handle_session_event +
  _handle_message_event and their SESSION_CREATED/SESSION_CLOSED/
  SESSION_TIMEOUT/MESSAGE_SENT subscriptions. The A2A live-view, rate-limit,
  usage, agent-lifecycle, and notification bridges are untouched.
- api/schemas/websocket.py: removed NewMessageBroadcast, WSMessageNew,
  WSMessageEdit, WSMessageDelete, WSSessionClosed — kept the WSMessage base
  class (still subclassed by the kept WSAgentStream/WSNotification) plus
  those two.
- api/schemas/groups.py: deleted (already fully orphaned since routes/
  groups.py was removed; its GroupResponse/GroupDetailResponse had zero
  consumers).

Updated the 5 websocket test files accordingly (removed the channel/
session-specific tests + fixed imports); test_websocket_bridge.py's
registration-coverage test dropped the SESSION_*/MESSAGE_SENT assertions.

Verified: full-suite collection (11943 tests, zero import errors) and a
complete test run (11549 passed, 394 skipped, 0 failed).

* docs: retire channels/sessions/messages from agent-facing docs + CLAUDE.md

Rewrites docs/rag (RAG-indexed) + docs/map + CLAUDE.md to reflect A2A (dm +
read_a2a) as primary agent comms; deletes the channel docs, splits messaging-tools
+ messaging-notification (renamed notification.md), swaps the WS worked example to
A2A_MESSAGE_SENT. _complete_map.md still needs regeneration (generated file).

* refactor(panel): remove Communications surface (channels/sessions)

Deletes the /communications routes, message components, task-detail Sessions tab,
use-channels + channel/session WS hooks, and the channels/sessions/messages/groups
api clients; prunes the Channel/Session/Message/Group types + mock data. (Auditor
live-feeds + dashboard.ts dead-route cleanup is a follow-up.)

* refactor(panel): drop auditor channel-feed + dead communication-metric route

* docs(map): regenerate _complete_map from updated slices

* fix(a2a): reduce get_unread_messages complexity below xenon C + stale comments

Extract the per-conversation unread-counter recompute into _reset_unread_counter
(the CI quality gate flagged get_unread_messages as rank C). Also drop the deleted
open_session from a content_actions comment and reword an evidence_repo docstring
that cited the removed messaging._notify_mentions.

---------

Co-authored-by: Renn F <rennf93@users.noreply.github.com>

docs/map/mcp-servers.md

@@ -14,7 +14,7 @@ The `roboco/mcp` package is the agent-side MCP gateway: a set of `FastMCP` serve
 | `roboco/mcp/utils.py` | Shared HTTP helpers: `_get_agent_headers`, `format_error_response`, `ApiResponse`, `ApiClient` (async httpx wrapper). Used by `optimal_server`, `docs_server`, `search_server`. | 383 |
 | `roboco/mcp/schemas/__init__.py` | Pydantic input models. After Phase-4 T9 deletions only `WriteDocInput` remains. | 35 |
 | `roboco/mcp/flow_server.py` | `roboco-flow` MCP server — intent verbs (lifecycle). Manifest-scoped registration, role-scoped path `/api/v1/flow/<route>/<verb>`, per-verb circuit breaker + 404-route synthesis. | 1028 |
-| `roboco/mcp/do_server.py` | `roboco-do` MCP server — content tools (commit, note, pitch, propose_roadmap, say, dm, notify, evidence, progress, sessions, playbook curation, pr_update). Manifest-scoped; fixed `/api/v1/do/<verb>` path; mirror circuit breaker. | 976 |
+| `roboco/mcp/do_server.py` | `roboco-do` MCP server — content tools (commit, note, pitch, propose_roadmap, dm, notify, evidence, progress, playbook curation, pr_update). Manifest-scoped; fixed `/api/v1/do/<verb>` path; mirror circuit breaker. | 976 |
 | `roboco/mcp/optimal_server.py` | `roboco-optimal` MCP server — RAG / KB / mentor / error / decision / standards / learnings / index-mgmt / proactive-context. Factory `create_optimal_mcp_server(agent_id)`; calls `/optimal/*`. | 1102 |
 | `roboco/mcp/docs_server.py` | `roboco-docs` MCP server — docs write/read/list/delete via `/docs/*`. Factory `create_docs_mcp_server(agent_id)`. RAG-based dedup on write. | 251 |
 | `roboco/mcp/git_readonly.py` | `roboco-git-readonly` MCP server — four read-only git views (status/log/diff/branch list) via `/api/git/*`. No breaker, no manifest. | 123 |
@@ -60,10 +60,10 @@ The `roboco/mcp` package is the agent-side MCP gateway: a set of `FastMCP` serve
 | `claim_pr_review` / `post_pr_review` / `claim_gate_review` / `pr_pass` / `pr_fail` | verb funcs | `flow_server.py:656–876` | PR-reviewer verbs (inbound + in-path gate). |
 | `i_will_plan` / `delegate` / `submit_up` / `submit_root` | verb funcs | `flow_server.py:759–856` | PM coordination verbs. |
 | `note` | verb func | `do_server.py:428` | Journal entry + handoff section writer (top-level `done`/`next` strings — the meltdown-#1 fix). |
-| `commit` / `say` / `dm` / `notify` / `evidence` | verb funcs | `do_server.py:423–598` | Core content tools. |
+| `commit` / `dm` / `notify` / `evidence` | verb funcs | `do_server.py:423–598` | Core content tools. |
 | `propose_roadmap` | verb func | `do_server.py:531` | Product Owner (board-roadmap-only, `_PRODUCT_OWNER_DO`): propose a themed roadmap cycle (goal + 3-7 item drafts) exactly once per exploration task. |
 | `draft_playbook` / `approve_playbook` / `reject_playbook` / `archive_playbook` | verb funcs | `do_server.py:600–644` | Playbook curation (delivery + Auditor). |
-| `progress` / `open_session` / `link_session` / `notify_list` / `notify_get` / `notify_ack` / `channels` / `pr_update` / `read_messages` | verb funcs | `do_server.py:646–840` | Wave-1 parity content tools. |
+| `progress` / `notify_list` / `notify_get` / `notify_ack` / `pr_update` / `read_messages` | verb funcs | `do_server.py:646–840` | Wave-1 parity content tools. |
 | `create_optimal_mcp_server` | factory | `optimal_server.py:1068` | Build `roboco-optimal-{agent_id}` server; registers 8 tool groups. |
 | `roboco_kb_search` / `roboco_rag_query` / `roboco_kb_stats` | tools | `optimal_server.py:70–213` | Search / RAG / stats. |
 | `roboco_ask_mentor` | tool | `optimal_server.py:371` | Primary conversational RAG tool (65s timeout). |
@@ -173,8 +173,8 @@ roboco/mcp/
 │   └── _load_manifest_flow_tools / _register_tools (fails loud if no manifest; ROBOCO_ALLOW_FULL_TOOLSET escape hatch)
 ├── do_server.py             # roboco-do (content tools)
 │   ├── mirror breaker machinery (_CIRCUIT_REJECTION_KINDS, _DICT_ERROR_CODE_MAP, _classify_*, _remediate_for_kind, _normalize_exception_envelope, _record_and_check_circuit)
-│   ├── commit, note (handoff done/next), pitch, propose_roadmap, say, dm, notify, evidence
-│   ├── progress, open_session, link_session, notify_list/get/ack, channels, pr_update, read_messages
+│   ├── commit, note (handoff done/next), pitch, propose_roadmap, dm, notify, evidence
+│   ├── progress, notify_list/get/ack, pr_update, read_messages
 │   ├── draft_playbook, approve_playbook, reject_playbook, archive_playbook
 │   └── _TOOLS / _load_manifest_do_tools / _register_tools (fails loud; ROBOCO_ALLOW_FULL_TOOLSET escape hatch)
 ├── optimal_server.py        # roboco-optimal (RAG/KB)
@@ -288,7 +288,7 @@ CLAUDE.md "MCP servers running per agent container" table lists 5 servers (`robo
 
 CLAUDE.md "roboco-optimal" row says the server exposes `roboco_ask_mentor`, `roboco_kb_search` only. The actual `optimal_server.py` registers **18** tools (search/rag/stats/index_code/index_docs/tokens_estimate/ask_mentor/search_error/record_error_solution/check_decision/record_decision/get_standards/validate_action/review_code/record_learning/search_learnings/clear_index/reindex_all/index_status/get_proactive_context). Understatement, not contradiction.
 
-CLAUDE.md "roboco-do" row lists `commit, note, say, dm, evidence` and (in the Agent Gateway section) `draft_playbook` for delivery roles + `approve_playbook`/`reject_playbook`/`archive_playbook` for the Auditor. The actual `do_server.py` `do_tools` registry also contains `pitch`, `propose_roadmap` (Product Owner only), `progress`, `open_session`, `link_session`, `notify`, `notify_list`, `notify_get`, `notify_ack`, `channels`, `pr_update`, `read_messages` — none mentioned in CLAUDE.md (`_TOOLS` is 21 entries, not the 5 named). Understatement.
+CLAUDE.md "roboco-do" row lists `commit, note, say, dm, evidence` and (in the Agent Gateway section) `draft_playbook` for delivery roles + `approve_playbook`/`reject_playbook`/`archive_playbook` for the Auditor. The actual `do_server.py` `do_tools` registry also contains `pitch`, `propose_roadmap` (Product Owner only), `progress`, `notify`, `notify_list`, `notify_get`, `notify_ack`, `pr_update`, `read_messages`, `read_a2a` — none mentioned in CLAUDE.md (`do_tools` is 18 entries, not the 5 named). Understatement.
 
 CLAUDE.md says the `note`/journal write "returns as soon as the entry is persisted; RAG indexing runs fire-and-forget." The MCP `note` tool itself is synchronous w.r.t. the orchestrator (a single POST); the fire-and-forget behavior is server-side, not visible in this slice — consistent, not drift.
 
@@ -335,7 +335,7 @@ No other commits in this slice since baseline.
 | `_register_tools` raises at import if manifest missing — local dev breakage | `flow_server.py:965`, `do_server.py:896` | **Mitigated (536bbb64):** `ROBOCO_ALLOW_FULL_TOOLSET` env var added as a dev/test escape hatch that bypasses the `RuntimeError` and registers the full tool set. Production behaviour is unchanged (ROBOCO_ALLOW_FULL_TOOLSET is not set in the orchestrator manifest). The mitigant must not leak into production containers. | low |
 | `propose_batch` well-formed filter could silently drop intended drafts | `intake_server.py:146` | **Partially mitigated (536bbb64 #163):** `_draft_title` now accepts `name` as a fallback for `title`, and `_normalize_batch_drafts` normalizes `name`-only drafts onto `title` before posting. Residual risk: a draft using a different key (e.g. `label`) is still dropped silently; the `dropped` count is sent but the CEO may not notice. | low |
 | Breaker SDK timeout (2s) may be too tight under load | `flow_server.py:55`, `do_server.py:37` | `_SDK_TIMEOUT=2.0` for the loopback `/verb/attempted` POST. Under container CPU contention the SDK could exceed 2s and the breaker fails open (returns original payload) — re-introducing the unbounded-retry condition the breaker was added to stop. Fail-open is safe but defeats the protection. | low |
-| Circuit-breaker forwarding does not pass `task_id` for content tools that lack one | `do_server.py:379` | `body.get("task_id")` is sent to the SDK. Several do-tools (`channels`, `read_messages`, `notify_list`) have no `task_id` — the breaker records `task_id=None`, so the per-verb (not per-task) breaker still works, but any future per-task breaker logic would mis-attribute these. | low |
+| Circuit-breaker forwarding does not pass `task_id` for content tools that lack one | `do_server.py:379` | `body.get("task_id")` is sent to the SDK. Several do-tools (`read_messages`, `notify_list`) have no `task_id` — the breaker records `task_id=None`, so the per-verb (not per-task) breaker still works, but any future per-task breaker logic would mis-attribute these. | low |
 
 ## Health