W6: Telegram notifications bridge (V1) (#524)

* feat(gateway): reviewer/PM collision map (W5)

The collision surface (intends_to_touch / adds_migration / touches_shared)
is authored at delegate time, consumed once by SequencingService to wire
dependency edges, then never shown to a reviewer again. This surfaces it:

- Pure builder (services/gateway/choreographer/collision.py): for a task
  under review, the surfaced siblings (same parent) that would collide —
  file-overlap globs or a shared migration chain (both adds_migration) —
  with the overlapping globs and a declared-vs-actual drift check. No
  DB/IO; callers fetch siblings (one indexed get_subtasks query, mig 069)
  + actual files (git). Caps: 10 siblings, 5 globs.

- Evidence envelopes: collision_context block injected into QA
  claim_review, PR-gate claim_gate_review (both carry real touched files
  so drift is populated), and the PM i_will_plan briefing (no actual
  files at plan time, drift omitted). Best-effort — a failure omits the
  block, never breaks the verb/briefing. Empty block omitted (zero token
  cost via _EVIDENCE_OMIT_WHEN_EMPTY).

- Panel: GET /api/tasks/{id}/collision-map (declared surface + sibling
  overlap; no drift — the panel route resolves no workspace) + a Collision
  tab on the task detail (8th tab). Mock-mode returns an empty map.

- docs/map added to the RAG auto-index dirs so the collision-map concept
  is fleet-retrievable; skipped gracefully if the dir is absent.

19 new tests (15 unit on the pure builder + 4 integration on the route).
Gate green: ruff/mypy/xenon (module rank A)/pytest 13000/coverage 94.81%,
panel typecheck/lint/516 tests.

* [w6-telegram] Add Telegram notifications bridge (V1)

CEO-facing Telegram DM bridge, flag-gated off by default
(ROBOCO_TELEGRAM_ENABLED). Mirrors the X-credentials / X-client pattern:

- TelegramCredentialsTable (migration 073) — singleton Fernet-encrypted
  bot_token + chat_id, all-or-nothing set/clear; API never returns plaintext.
- TelegramClient ABC / NullTelegramClient (no-op, configured->False, never
  raises) / LiveTelegramClient (httpx POST sendMessage) / build_telegram_client
  factory (Null when creds unset).
- /telegram/credentials CEO-only routes (write-only, guard-decorated).
- Best-effort _notify_telegram fan-out from the two CEO-notify producers
  (notify_ceo_of_escalation, notify_ceo_of_completion) — guarded by the flag,
  never raises into the producer, carries a panel deep-link when
  panel_base_url is set.
- panel credentials card (2 fields) nested in the Telegram feature-flag row.
- panel_base_url + telegram_timeout_seconds config fields.

V1 scope only: credentials + flag + panel card + client + one-line fan-out.
Out of scope (V2): inbound commands, a TelegramEngine background loop, a
dedup ledger, a bus subscription.

* [w6-telegram] fix: slave mypy/xenon regression (product tests + helper extract)

Pre-existing on slave from prior session's merges — no PR's CI caught them
(squash merges don't re-CI the result; each branch was based on older slave).

- test_product: _product helper returned MagicMock -> list invariant error;
  cast to ProductTable, move import under TYPE_CHECKING.
- test_usage: svc.session.execute (AsyncSession) has no call_args_list;
  cast to MagicMock at the two call sites.
- product.progress_for_products: xenon rank C -> extract module-level
  _project_to_products_map helper (repo pattern: helper-extract).

---------

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

alembic/versions/074_telegram_credentials.py

@@ -0,0 +1,41 @@
+"""Add the telegram_credentials table — the Telegram notifications bridge.
+
+Singleton row (mirrors ``x_credentials``, migration 059) holding the
+Fernet-encrypted bot token (from @BotFather) + chat id (the CEO's
+destination). Additive and inert until real Telegram credentials are set and
+``telegram_enabled`` is armed.
+
+Revision ID: 074_telegram_credentials
+Revises: 073_project_environments
+Create Date: 2026-07-14
+"""
+
+from __future__ import annotations
+
+import sqlalchemy as sa
+from alembic import op
+
+revision = "074_telegram_credentials"
+down_revision = "073_project_environments"
+branch_labels: dict[str, str] | None = None
+depends_on: dict[str, str] | None = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "telegram_credentials",
+        sa.Column("id", sa.UUID(as_uuid=True), primary_key=True, nullable=False),
+        sa.Column("bot_token_encrypted", sa.Text(), nullable=True),
+        sa.Column("chat_id_encrypted", sa.Text(), nullable=True),
+        sa.Column(
+            "created_at",
+            sa.DateTime(timezone=True),
+            nullable=False,
+            server_default=sa.text("now()"),
+        ),
+        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=True),
+    )
+
+
+def downgrade() -> None:
+    op.drop_table("telegram_credentials")