fix: disable Telegram link-preview in tracker notifications (ORCH-080)

Add "disable_web_page_preview": True to the JSON payload of both
low-level Telegram primitives — send_telegram (POST /sendMessage) and
edit_telegram (POST /editMessageText). Telegram no longer expands the
Plane "Modern project management" link-preview banner under every
tracker card (bump/edit) and notify/alert message, which the default
bump mode (ORCH-067) was duplicating on each transition.

Single-point fix at the primitive level — all consumers
(update_task_tracker, notify_approve_requested, notify_error, stage
alerts from launcher/stage_engine) inherit it without code changes.
parse_mode: HTML is preserved so the ORCH-NNN issue link stays
clickable; disable_notification, bump/edit logic, the one-card-per-task
invariant, return contracts and never-raise are untouched. Unconditional,
no kill-switch (ADR-001).

Tests: tests/test_link_preview_disabled.py (TC-01..06). Docs: CHANGELOG,
CLAUDE.md, docs/architecture/README.md (Notifications component).

Refs: ORCH-080
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tests/test_link_preview_disabled.py

@@ -0,0 +1,159 @@
+"""ORCH-080 — suppress Telegram link-preview in tracker/notify primitives.
+
+Both low-level primitives ``send_telegram`` (POST /sendMessage) and
+``edit_telegram`` (POST /editMessageText) must add
+``"disable_web_page_preview": True`` to their JSON payload, so the Plane
+"Modern project management" banner no longer expands under every tracker card /
+notification. The clickable issue link must stay clickable -> ``parse_mode:
+"HTML"`` is preserved in both payloads, and the never-raise / return contracts
+are unchanged.
+
+Network is isolated: ``src.notifications.httpx`` is patched; creds are stubbed.
+Test ids TC-01..TC-06 from 04-test-plan.yaml.
+"""
+
+import os
+import tempfile
+from unittest.mock import MagicMock, patch
+
+os.environ.setdefault("ORCH_PLANE_API_TOKEN", "test-token")
+os.environ.setdefault("ORCH_GITEA_TOKEN", "test-token")
+
+_test_db = os.path.join(tempfile.gettempdir(), "test_orchestrator_link_preview.db")
+os.environ.setdefault("ORCH_DB_PATH", _test_db)
+
+from src import notifications as N  # noqa: E402
+
+# conftest._no_telegram autouse-patches src.notifications.send_telegram to a
+# no-op for every test (prod-leak guard). Capture the REAL implementation at
+# import time (before any fixture runs) so these payload tests can exercise it.
+_REAL_SEND = N.send_telegram
+
+
+def _patch_tg_creds(monkeypatch):
+    monkeypatch.setattr(N._get_settings(), "telegram_bot_token", "T", raising=False)
+    monkeypatch.setattr(N._get_settings(), "telegram_chat_id", "C", raising=False)
+
+
+def _ok_resp(message_id=42):
+    resp = MagicMock()
+    resp.json.return_value = {"ok": True, "result": {"message_id": message_id}}
+    return resp
+
+
+# --------------------------------------------------------------------------- #
+# TC-01 — send_telegram sets disable_web_page_preview: True
+# --------------------------------------------------------------------------- #
+def test_send_telegram_disables_link_preview(monkeypatch):
+    _patch_tg_creds(monkeypatch)
+    with patch("src.notifications.httpx") as hx:
+        hx.post.return_value = _ok_resp()
+        _REAL_SEND("hello")
+    payload = hx.post.call_args.kwargs["json"]
+    assert payload["disable_web_page_preview"] is True
+
+
+# --------------------------------------------------------------------------- #
+# TC-02 — edit_telegram sets disable_web_page_preview: True
+# --------------------------------------------------------------------------- #
+def test_edit_telegram_disables_link_preview(monkeypatch):
+    _patch_tg_creds(monkeypatch)
+    with patch("src.notifications.httpx") as hx:
+        hx.post.return_value = _ok_resp()
+        N.edit_telegram(1, "hello")
+    payload = hx.post.call_args.kwargs["json"]
+    assert payload["disable_web_page_preview"] is True
+
+
+# --------------------------------------------------------------------------- #
+# TC-03 — parse_mode HTML preserved in both payloads (clickable <a href>)
+# --------------------------------------------------------------------------- #
+def test_send_telegram_keeps_parse_mode_html(monkeypatch):
+    _patch_tg_creds(monkeypatch)
+    with patch("src.notifications.httpx") as hx:
+        hx.post.return_value = _ok_resp()
+        _REAL_SEND("hello")
+    assert hx.post.call_args.kwargs["json"]["parse_mode"] == "HTML"
+
+
+def test_edit_telegram_keeps_parse_mode_html(monkeypatch):
+    _patch_tg_creds(monkeypatch)
+    with patch("src.notifications.httpx") as hx:
+        hx.post.return_value = _ok_resp()
+        N.edit_telegram(1, "hello")
+    assert hx.post.call_args.kwargs["json"]["parse_mode"] == "HTML"
+
+
+# --------------------------------------------------------------------------- #
+# TC-04 — send_telegram preserves existing fields + disable_notification arg
+# --------------------------------------------------------------------------- #
+def test_send_telegram_preserves_existing_fields(monkeypatch):
+    _patch_tg_creds(monkeypatch)
+    with patch("src.notifications.httpx") as hx:
+        hx.post.return_value = _ok_resp()
+        _REAL_SEND("body", disable_notification=True)
+    payload = hx.post.call_args.kwargs["json"]
+    assert payload["chat_id"] == "C"
+    assert payload["text"] == "body"
+    assert payload["parse_mode"] == "HTML"
+    assert payload["disable_notification"] is True
+
+
+def test_send_telegram_disable_notification_default_false(monkeypatch):
+    _patch_tg_creds(monkeypatch)
+    with patch("src.notifications.httpx") as hx:
+        hx.post.return_value = _ok_resp()
+        _REAL_SEND("body")
+    assert hx.post.call_args.kwargs["json"]["disable_notification"] is False
+
+
+def test_edit_telegram_preserves_existing_fields(monkeypatch):
+    _patch_tg_creds(monkeypatch)
+    with patch("src.notifications.httpx") as hx:
+        hx.post.return_value = _ok_resp()
+        N.edit_telegram(7, "body")
+    payload = hx.post.call_args.kwargs["json"]
+    assert payload["chat_id"] == "C"
+    assert payload["message_id"] == 7
+    assert payload["text"] == "body"
+    assert payload["parse_mode"] == "HTML"
+
+
+# --------------------------------------------------------------------------- #
+# TC-05 — return contracts unchanged
+# --------------------------------------------------------------------------- #
+def test_send_telegram_returns_message_id(monkeypatch):
+    _patch_tg_creds(monkeypatch)
+    with patch("src.notifications.httpx") as hx:
+        hx.post.return_value = _ok_resp(message_id=99)
+        assert _REAL_SEND("x") == 99
+
+
+def test_send_telegram_returns_none_without_creds(monkeypatch):
+    monkeypatch.setattr(N._get_settings(), "telegram_bot_token", "", raising=False)
+    monkeypatch.setattr(N._get_settings(), "telegram_chat_id", "", raising=False)
+    assert _REAL_SEND("x") is None
+
+
+def test_edit_telegram_returns_edit_ok(monkeypatch):
+    _patch_tg_creds(monkeypatch)
+    with patch("src.notifications.httpx") as hx:
+        hx.post.return_value = _ok_resp()
+        assert N.edit_telegram(1, "x") == N.EDIT_OK
+
+
+# --------------------------------------------------------------------------- #
+# TC-06 — never-raise: httpx.post raising -> None / EDIT_FAILED
+# --------------------------------------------------------------------------- #
+def test_send_telegram_never_raises(monkeypatch):
+    _patch_tg_creds(monkeypatch)
+    with patch("src.notifications.httpx") as hx:
+        hx.post.side_effect = Exception("boom")
+        assert _REAL_SEND("x") is None
+
+
+def test_edit_telegram_never_raises(monkeypatch):
+    _patch_tg_creds(monkeypatch)
+    with patch("src.notifications.httpx") as hx:
+        hx.post.side_effect = Exception("boom")
+        assert N.edit_telegram(1, "x") == N.EDIT_FAILED