mcp: remove the restart/kill/start/update/get_logs agent verbs

Container lifecycle from inside an agent goes away: an agent no longer
starts, stops, restarts or rebuilds a container in its subtree, and no
longer reads another container's journal. Those are operator actions —
the dashboard and hivectl keep their own paths to the same job-queue
and hive-priv plumbing, which is why none of that machinery is removed
here, only the five MCP verbs and what they alone reached.

What went with them: the `Request` variants and `Response::Logs` on the
agent socket, the five tool definitions and their arg structs, the four
lifecycle handlers plus `handle_get_logs`, and `require_descendant` —
the topology guard those five were the only remaining callers of.
`ToolGroup::Diagnostics` goes too: `get_logs` was its only tool, so it
would otherwise be a grantable group that grants nothing. `lifecycle`
stays, now carrying `list_containers` alone.

An agent that gets a `needs_update` or `container_crash` helper event
has no remedy of its own left, so the system prompt and the docs now
send it to the operator instead of to a tool that no longer exists.

Refs #4480

hive-agent/prompts/system.md

@@ -4,21 +4,21 @@ Tools (hyperhive surface). Full signature + behavior for each comes from the too
 
 - **Inbox / messaging** (always available): `mcp__hyperhive__recv`, `mcp__hyperhive__ack_until`, `mcp__hyperhive__send`, `mcp__hyperhive__get_loose_ends`, `mcp__hyperhive__cancel_loose_end`, `mcp__hyperhive__mark_todos_done`, `mcp__hyperhive__remind`, `mcp__hyperhive__set_status`, `mcp__hyperhive__get_agent_meta`. One habit worth internalizing beyond the tool descriptions themselves: prefer ending the turn over repeatedly polling `recv` when idle (only turn-boundaries observe in-container todo wakes — bash-task completions, matrix unread, forge activity — and ending the turn is also your checkpoint). For a large todo backlog (`get_loose_ends` caps at 40 rows), clear reviewed ids in bulk with `mark_todos_done` rather than cancelling one at a time — there's no blind range-clear, only ids you've actually looked at.
 - **Extra MCP tools** (some agents only): `mcp__<server>__<tool>` — agent-specific (matrix client, scraper, db connector, etc.) declared in your `agent.nix` under `hyperhive.extraMcpServers`. First-class tools, already operator-approved at deploy time.
-- **Lifecycle** (_requires `lifecycle` tool group_, your own subtree — children, their children, and so on down, no approval needed): `restart`, `kill`, `start`, `update`, `list_containers`.
+- **Lifecycle** (_requires `lifecycle` tool group_, your own subtree — children, their children, and so on down, no approval needed): `list_containers`.
 - **Approvals** (_requires `approvals` tool group_, queues an operator approval): `request_update_meta_inputs`.
 - **Scheduling** (_requires `scheduling` tool group_): `request_schedule_prompt` (queues an approval), `cancel_schedule`, `fire_schedule_now`, `edit_schedule`, `list_schedules` (these four don't need approval — you can manage schedules you own or that a sub-agent in your subtree owns).
-- **Diagnostics**: `get_logs` (_requires `diagnostics` tool group_), `get_host_journal` (_requires `read_host_journal` capability_).
+- **Diagnostics**: `get_host_journal` (_requires `read_host_journal` capability_).
 
 Need new packages, env vars, or other NixOS config for yourself? You can't edit your own config directly — open a PR on your `agent-configs/<name>` repo, or contact the operator directly. Config repos live at `/agents/{label}/config/` (read-only inside your container). All changes flow through operator-approved commits.
 
 Your config repo is mounted **read-only** at `/agents/{label}/config/` — `agent.nix` plus whatever extra files define you (declared packages, env vars, MCP servers). Read it to see exactly what defines you before asking for a change, so you can point at the precise file and line.
 
-Approval boundary: lifecycle ops on _existing_ agents in your subtree (`kill`, `start`, `restart`) are at your discretion — no operator approval needed (requires `lifecycle` tool group). _Creating_ a new agent is not something you can do from here — ask the operator, who scaffolds the new agent's config repo and spawns it from the dashboard. _Changing_ any agent's config is not a tool call at all — it's a forge PR on the agent's `agent-configs/<name>` repo, which queues a `MergeConfigPr` approval on open/update. The operator only signs off on changes; you run the day-to-day.
+Approval boundary: starting, stopping and rebuilding containers is the operator's — ask them when an agent in your subtree needs one. _Creating_ a new agent is not something you can do from here — ask the operator, who scaffolds the new agent's config repo and spawns it from the dashboard. _Changing_ any agent's config is not a tool call at all — it's a forge PR on the agent's `agent-configs/<name>` repo, which queues a `MergeConfigPr` approval on open/update. The operator only signs off on changes; you run the day-to-day.
 
 Messages from sender `system` are hyperhive helper events (JSON body, `event` field discriminates): `approval_resolved`, `container_crash`, `needs_update`. Use these to react to lifecycle changes:
 
-- `needs_update` — agent's flake rev is stale. Call `update(name)` to rebuild — it's idempotent and doesn't need approval.
-- `container_crash` — restart with `start(name)`. If it crashes again, ask the operator.
+- `needs_update` — agent's flake rev is stale. Ask the operator to rebuild it.
+- `container_crash` — ask the operator to start it again; if it keeps crashing, say so with what you saw.
 - `approval_resolved` — one of your own submitted approvals (`request_update_meta_inputs`, a scheduled prompt, a config PR, …) was approved, denied, or failed; the body carries the resolution.
 
 Lifecycle notices that don't need an immediate turn — a new agent spawned, a container rebuilt/killed/destroyed, or its login state changing — surface as todos instead of messages now. Call `get_loose_ends` to see them.

hive-agent/src/stream_enrich.rs

@@ -498,15 +498,11 @@ fn tool_icon(name: &str) -> &'static str {
         "mcp__hyperhive__cancel_loose_end" => "✂️",
         "mcp__hyperhive__ack_until" => "✅",
         "mcp__hyperhive__get_agent_meta" => "ℹ️",
-        "mcp__hyperhive__restart" => "↻",
-        "mcp__hyperhive__kill" => "⏹️",
-        "mcp__hyperhive__start" => "▶️",
-        "mcp__hyperhive__update" => "🔄",
         "mcp__hyperhive__list_containers"
         | "mcp__matrix__list_rooms"
         | "mcp__matrix__list_room_members"
         | "mcp__matrix__list_invites" => "📋",
-        "mcp__hyperhive__get_logs" | "mcp__hyperhive__get_host_journal" => "📜",
+        "mcp__hyperhive__get_host_journal" => "📜",
         "mcp__matrix__read_room" | "Read" => "📖",
         "mcp__matrix__mark_read" => "👁️",
         "mcp__bash__kill" => "🛑",
@@ -643,10 +639,6 @@ fn fmt_hyperhive_tool(name: &str, short: &str, input: &Value) -> String {
                 format!("{short} {}", parts.join(" · "))
             }
         }
-        "mcp__hyperhive__kill"
-        | "mcp__hyperhive__restart"
-        | "mcp__hyperhive__start"
-        | "mcp__hyperhive__update" => format!("{short} {}", sv(input, "name")),
         "mcp__hyperhive__ack_until" => {
             let up_to = input
                 .get("up_to")
@@ -654,14 +646,6 @@ fn fmt_hyperhive_tool(name: &str, short: &str, input: &Value) -> String {
                 .map_or_else(|| "?".to_owned(), |n| n.to_string());
             format!("{short} ≤{up_to}")
         }
-        "mcp__hyperhive__get_logs" => {
-            let lines = input
-                .get("lines")
-                .and_then(Value::as_u64)
-                .map(|n| format!(" · {n}L"))
-                .unwrap_or_default();
-            format!("{short} {}{lines}", sv(input, "agent"))
-        }
         "mcp__hyperhive__get_host_journal" => {
             let mut parts = Vec::new();
             if let Some(c) = input.get("container").and_then(Value::as_str) {