fix(gateway): notify home channel on ordinary startup

[dabuge]

Summary

• Send home-channel startup notifications for ordinary gateway starts, boot autostarts, Scheduled Task launches, service restarts, and other non-chat-initiated restarts once a platform is connected.
• Keep chat-originated /restart behavior targeted to the initiating chat/topic only, avoiding an extra home-channel broadcast.
• Add tests for the startup-notification decision helper.

Test Plan

• uv run --extra dev pytest -o addopts='' tests/gateway/test_restart_notification.py::test_home_channel_startup_notice_sent_for_plain_startup tests/gateway/test_restart_notification.py::test_home_channel_startup_notice_suppressed_for_chat_originated_restart tests/gateway/test_restart_notification.py::test_send_home_channel_startup_notification_to_configured_home -q
• uv run --extra dev pytest -o addopts='' tests/gateway/test_restart_notification.py -q

Manual verification

• Restarted the local Windows Scheduled Task gateway and verified the log line: Sent home-channel startup notification to feishu:oc_....

[alt-glitch]

Related: #24271 (opt-in startup-notification flag), #27278 (unconditional every-start), #30787 (per-platform opt-in), and issue #27870. This PR uses a startup-notification decision helper that fires on non-chat-initiated restarts while keeping /restart targeted to the initiating chat — a different mechanism than the opt-in-flag and unconditional approaches. Competing same-feature cluster; maintainer chooses the mechanism.

[alaamohanad169-ship-it]

Acknowledged: noted competing PR(s) #24271, #27278, #30787, #27870. My approach differs and is complementary, not mutually exclusive. Open to consolidating if reviewers prefer one direction.

[teknium1]

Thanks for the focused gateway fix. The underlying gap is still present on current main: gateway/run.py:7307-7313 only sends the home-channel online message when .restart_pending.json exists, so an ordinary startup remains silent.

Problems

• The new tests cover only _should_send_home_channel_startup_notification; they do not exercise the real startup sequence that captures markers before _send_restart_notification() consumes .restart_notify.json (gateway/run.py:7291-7300).

Suggested changes

• Salvage the predicate/call into the current startup block while preserving _booted_from_restart handling and planned-marker cleanup at gateway/run.py:7292-7313.
• Add lifecycle tests for an ordinary no-marker startup sending one home notice and a chat-originated /restart suppressing that broadcast.

Automated hermes-sweeper review.

[teknium1]

These truth-table checks do not verify the production ordering around _send_restart_notification(), which consumes the chat marker. Please add lifecycle coverage for a no-marker startup send and a chat-originated restart suppressing the home-channel send.