remove the list_containers and request_update_meta_inputs MCP tools

Both agent-facing tools go away end to end, with no replacement. This is
an intentional capability removal: agents can no longer enumerate their
own subtree, and can no longer queue a meta-flake input bump.

The system prompt and docs/tools/lifecycle.md land in this same commit
on purpose. A tool named in the prompt but absent from the server makes
agents confidently call something that doesn't exist, and the failure
then surfaces far from its cause.

Removed:

- MCP registrations and bodies (hive-agent-mcp), plus the now-unused
  UpdateMetaInputsArgs.
- Wire variants Request::ListDescendants,
  Request::RequestUpdateMetaInputs and Response::Containers, plus
  ContainerInfo, whose only consumer was that response.
- hive-c0re's handle_list_descendants (its whole module) and
  handle_request_update_meta_inputs, the two dispatch arms, and the
  require_group(agent, "approvals", ...) gate on the meta-inputs verb.
- The stream_enrich emoji entry and argument formatter.
- docs/tools/lifecycle.md (both tools it documented are gone), its two
  referrers, the tool-group tables and the agent-hierarchy prose.

Tool groups are kept, deliberately. ToolGroup::Lifecycle listed exactly
one tool and now lists none — it is vestigial, but the variant stays so
existing meta/capabilities.json grants still parse; retiring it is a
separate decision. ToolGroup::Approvals also listed exactly one tool,
but the group is NOT dead: check_can_cancel_approval still gates
cancel_loose_end's approval-cancel arm on it server-side.

ApprovalKind::UpdateMetaInputs stays too. Nothing in production code
produces it any more, but pre-existing approval rows may still carry it,
and the operator's own path to a meta update is unaffected — the
dashboard's POST /api/meta-update inserts the meta_update job directly,
bypassing approvals entirely.

The two format_ack tests in hive-agent-mcp that named
request_update_meta_inputs were only using it as a label string while
exercising the generic OkWarn/Ok renderer, so they are retargeted to a
surviving tool rather than deleted.

Note hive-c0re's priv_client::list_containers is a different thing (the
host-side privileged container listing behind hive-priv) and is
untouched.

Closes #4591

hive-sh4re/src/container.rs

@@ -1,19 +1,10 @@
-//! Container/agent-roster wire shapes: what `ListDescendants` and
-//! `HostRequest::AgentStatus` return, plus the per-account matrix
-//! identity shape surfaced by `GetAgentMeta`.
+//! Container/agent-roster wire shapes: what `HostRequest::AgentStatus`
+//! returns, plus the per-account matrix identity shape surfaced by
+//! `GetAgentMeta`.
 
 use chrono::{DateTime, Utc};
 use serde::{Deserialize, Serialize};
 
-/// One entry in a `ListDescendants` result.
-#[derive(Debug, Clone, Serialize, Deserialize)]
-pub struct ContainerInfo {
-    /// Logical agent name (no `h-` prefix).
-    pub name: String,
-    /// Whether the container is currently running.
-    pub running: bool,
-}
-
 /// One row in a `HostRequest::AgentStatus` result — the operator-CLI
 /// projection of the dashboard's per-agent `ContainerView`. Carries the
 /// agent's running/health flags plus the technical state an operator

hive-sh4re/src/permissions.rs

@@ -152,9 +152,15 @@ pub enum ToolGroup {
     Meta,
     /// `get_loose_ends`, `cancel_loose_end`, `remind`
     Inbox,
-    /// `list_containers` - *(privileged)*
+    /// Gates no tool today — `list_containers`, its only member, was
+    /// removed with no replacement. Kept so existing
+    /// `meta/capabilities.json` grants still parse; `tools()` returns
+    /// `&[]`.
     Lifecycle,
-    /// `request_update_meta_inputs` - *(privileged)*
+    /// Grants no MCP tool today — `request_update_meta_inputs`, its only
+    /// member, was removed with no replacement. Still a live
+    /// server-side gate: `cancel_loose_end`'s approval-cancel arm
+    /// requires it (`socket_server::check_can_cancel_approval`).
     Approvals,
     /// `request_schedule_prompt`, `fire_schedule_now`, `cancel_schedule`,
     /// `edit_schedule`, `list_schedules` - *(privileged)*
@@ -215,16 +221,15 @@ impl ToolGroup {
     }
 
     /// The MCP tool names (without the `mcp__hyperhive__` prefix) in this group.
-    /// Returns `&[]` for `WebTools` — it enables Claude built-in tools,
-    /// not MCP tools; see `builtin_tools()`.
+    /// Returns `&[]` for `WebTools` (it enables Claude built-in tools, not MCP
+    /// tools — see `builtin_tools()`) and for `Lifecycle` / `Approvals`
+    /// (their tools were removed); see each variant's doc comment.
     #[must_use]
     pub fn tools(self) -> &'static [&'static str] {
         match self {
             Self::Messaging => &["send", "recv", "ack_until"],
             Self::Meta => &["get_agent_meta"],
             Self::Inbox => &["get_loose_ends", "cancel_loose_end", "remind"],
-            Self::Lifecycle => &["list_containers"],
-            Self::Approvals => &["request_update_meta_inputs"],
             Self::Scheduling => &[
                 "request_schedule_prompt",
                 "fire_schedule_now",
@@ -233,16 +238,22 @@ impl ToolGroup {
                 "list_schedules",
             ],
             Self::Forge => &["create_repo"],
-            // Both empty, for different reasons — see each variant's own
-            // doc comment above. `Execution` grants the out-of-process
-            // `bash` MCP server (`mcp__bash__run`/`status`/`kill`), gated
-            // at config-render time by `extra_server_required_group` in
+            // All four empty, for four different reasons — see each
+            // variant's own doc comment above. `Execution` grants the
+            // out-of-process `bash` MCP server
+            // (`mcp__bash__run`/`status`/`kill`), gated at config-render
+            // time by `extra_server_required_group` in
             // `hive-agent/src/mcp_config.rs`, not by this list — an
             // out-of-process server has no later enforcement point, so
             // that gate is the actual security boundary. `WebTools`
             // grants Claude built-in tools, not MCP ones; see
-            // `builtin_tools()`.
-            Self::Execution | Self::WebTools => &[],
+            // `builtin_tools()`. `Lifecycle` and `Approvals` each listed
+            // exactly one tool — `list_containers` and
+            // `request_update_meta_inputs` respectively — and both tools
+            // were removed outright; the variants stay so existing
+            // grants parse, and `Approvals` still gates
+            // `cancel_loose_end`'s approval-cancel arm server-side.
+            Self::Lifecycle | Self::Approvals | Self::Execution | Self::WebTools => &[],
         }
     }
 
@@ -324,9 +335,9 @@ impl ToolGroup {
                 "get_agent_meta — identity introspection (set_status is always available)"
             }
             Self::Inbox => "get_loose_ends, cancel_loose_end, remind — self-scheduling",
-            Self::Lifecycle => "list_containers — own-subtree container listing (privileged)",
+            Self::Lifecycle => "no tools — vestigial since list_containers was removed",
             Self::Approvals => {
-                "request_update_meta_inputs — operator-approved meta-flake input bumps (privileged)"
+                "no tools — grants cancel_loose_end's approval-cancel arm (privileged)"
             }
             Self::Scheduling => {
                 "request_schedule_prompt and related — operator-visible scheduled prompts (privileged)"