fix(serve): register shell hooks on dashboard/serve startup

[LiTerBo]

Problem

The desktop app and remote backends run agent turns through serve's in-process /api/ws gateway, but shell-hook registration lived only in _prepare_agent_startup, gated on _AGENT_COMMANDS = {None, "chat", "acp", "rl"} (+ cron/gateway/mcp subcommands). serve/dashboard are deliberately absent from that set, so lifecycle hooks (e.g. mnemon prime/remind/nudge) never registered on the headless path.

Fix

Extract a shared _register_shell_hooks() helper and call it from both:

• _prepare_agent_startup (interactive agent entrypoints), and
• cmd_dashboard (the headless serve backend + dashboard)

so hooks fire regardless of how the agent turn is hosted.

Tests

• test_serve_registers_shell_hooks: serve registers hooks on startup
• test_register_shell_hooks_wires_shell_and_outbound: the helper wires both shell and outbound webhooks

Context

Follow-up to #92655, which added the shared registration path but left serve/dashboard gated out.

[Enough1122]

AI code review — automated review for reference; please use your judgment.

Chunk5 review — fix(serve): register shell hooks on dashboard/serve startup

Right fix for a real gap: serve hosts agent turns via in-process /api/ws but was excluded from the _AGENT_COMMANDS gate, so lifecycle hooks silently never fired there.

• hermes_cli/main.py:12401-12408 — registering with accept_hooks=False on the headless path is the safe choice (no interactive acceptance). Correct.
• hermes_cli/main.py:12662-12696 — extracting _register_shell_hooks removes the duplication rather than adding a second copy. The refactor of _prepare_agent_startup to call it preserves the _accept_hooks behaviour on interactive paths. Verified no behaviour change there.
• tests/hermes_cli/test_dashboard_shell_hooks.py:1-102 — regression test names the exact gate (_AGENT_COMMANDS exclusion) so a future refactor that re-breaks this fails loudly.
• Non-blocking: confirm register_from_config is idempotent, since cmd_dashboard + a later _prepare_agent_startup in the same process would now run it twice (the docstring claims idempotency — trusting it, just flagging the double-registration path exists).

Non-blocking. Merge-ready.

[kvnloo]

exact-head c1ae41e — void if moved

CHECK / pick-one: serve-path registration via hermes_cli/main.py only. Prefer #111315 (TUI+serve+shared helper+parity test).

Recommend: close as duplicate of the #111315 consolidation, or fold the test_dashboard_shell_hooks coverage into #111315 if anything unique remains.