Remove references to the deleted /agent-notify endpoint

[malpern]

The problem

786227c ("Delete agent-speech subsystem") removed /agent-notify, AgentNotificationKind, agentSpeechMode/Verbosity, and the agent_notify_url status key. The code change was complete; the docs and commands around it were not.

What was actually broken for users:

• voxclaw-say has no --kind flag (correctly removed in 913985b for the /read-only architecture), but .claude/commands/voxclaw-summary.md, voxclaw-progress.md and voxclaw-failure.md all still piped through --kind. All three printed usage and exited 2 instead of speaking.
• CLAUDE.md and AGENTS.md instructed every agent working in this repo to invoke voxclaw-say --kind summary, so the documented speech convention could never succeed.
• CLAUDE.md justified always emitting via the agentSpeechMode setting, which no longer exists.
• SKILL.md — served to agents as skill_doc in the /status payload — documented POST /agent-notify with a required kind field, a {"status":"suppressed"} response, and agent_speech_mode/verbosity status keys. Agents following it would POST to an endpoint that 404s.
• GET /status itself advertised agent_notify_url in its agent_handoff string, pointing agents at the dead endpoint.

The fix

Docs, demo, and slash commands now describe the /read-only architecture the code implements. README.md and SKILL.md's 404 row list the routes that actually exist (/read, /ack, /control, /status, /claw). The presentation's "three endpoints" list swaps the dead entry for POST /ack, which is real.

AgentHandoffPrompt already had a test asserting it contains no agent_notify, but the hardcoded duplicate string in NetworkSession.handleStatus wasn't covered — which is exactly how it survived the original cleanup. The status integration test now asserts the same thing about the served payload.

docs/refactor-roadmap.md is left alone: it correctly records the removal as history.

Verification

• swift build clean; swift test — 279 tests in 35 suites pass.
• Confirmed the new assertion actually guards: re-introducing agent_notify_url into the status string makes statusEndpointReturnsOK fail on !body.contains("agent_notify"), and removing it passes again.
• grep for agent-notify/agent_notify/--kind/agentSpeech/suppressed across the repo returns nothing outside the roadmap doc and the tests that assert their absence.

🤖 Generated with Claude Code