hive-c0re: remove the approvals subsystem

Nothing submits an approval since scheduled prompts left hive-c0re, so the
queue only acted on rows written before that.

- hive-c0re: the approvals store and its migrations, approve/deny/
  resolve actions, the ResolveApproval tail node (and meta_update's
  approval_id), POST /api/approve and /api/deny, the approval views on
  /api/state, the approval_resolved dashboard event, the orphan GC,
  destroy/purge failing pending rows, and the approval rows in
  get_loose_ends. DestroyBookkeeping loses the purge flag, which only
  worded the approval-failure note.
- The CancelLooseEnd request goes: its only hive-c0re arm was the
  approval one. cancel_loose_end handles reminder and todo in the harness.
- Wire types: hive_sh4re::approvals (ReminderStats moves to inbox),
  LooseEnd::Approval, CancelLooseEndKind, HelperEvent::ApprovalResolved,
  ToolGroup::Approvals, HostRequest::{Pending,Approve,Deny} and
  HostResponse.approvals. HOST_SOCK_VERSION goes to 2 for the removed
  field.
- hivectl loses the approvals verbs; docs/tools/hivectl-cli.md is
  regenerated.
- The system prompt drops approval_resolved.
- The approvals table stays in broker.sqlite, unread, the same way the
  operator_questions table was left when its store was removed.
- An `approvals` entry still in tool-groups.json is skipped with a warning
  by ToolGroup::parse_list, like any unknown group.
- docs/agent-lifecycle/approvals.md is renamed to config-changes.md so the
  code's doc pointers resolve; its content follows in the docs commit.

hive-sh4re/src/permissions.rs

@@ -157,11 +157,6 @@ pub enum ToolGroup {
     /// `meta/capabilities.json` grants still parse; `tools()` returns
     /// `&[]`.
     Lifecycle,
-    /// 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,
     /// Gates no tool today — `create_repo`, its only member, was removed
     /// with no replacement. Kept so existing `meta/capabilities.json`
     /// grants still parse; `tools()` returns `&[]`.
@@ -219,15 +214,15 @@ 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()`) and for `Lifecycle` / `Approvals` /
-    /// `Forge` (their tools were removed); see each variant's doc comment.
+    /// tools — see `builtin_tools()`) and for `Lifecycle` / `Forge` (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"],
-            // All five empty, for different reasons — see each
+            // All four 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
@@ -236,15 +231,11 @@ impl ToolGroup {
             // 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()`. `Lifecycle`, `Approvals` and `Forge` each
-            // listed exactly one tool — `list_containers`,
-            // `request_update_meta_inputs` and `create_repo` respectively
-            // — and all three 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::Forge | Self::Execution | Self::WebTools => {
-                &[]
-            }
+            // `builtin_tools()`. `Lifecycle` and `Forge` each listed
+            // exactly one tool — `list_containers` and `create_repo`
+            // respectively — and both tools were removed outright; the
+            // variants stay so existing grants parse.
+            Self::Lifecycle | Self::Forge | Self::Execution | Self::WebTools => &[],
         }
     }
 
@@ -297,7 +288,6 @@ impl ToolGroup {
         Self::Meta,
         Self::Inbox,
         Self::Lifecycle,
-        Self::Approvals,
         Self::Execution,
     ];
 
@@ -309,7 +299,6 @@ impl ToolGroup {
         Self::Meta,
         Self::Inbox,
         Self::Lifecycle,
-        Self::Approvals,
         Self::Forge,
         Self::Execution,
         Self::WebTools,
@@ -325,9 +314,6 @@ impl ToolGroup {
             }
             Self::Inbox => "get_loose_ends, cancel_loose_end, remind — self-scheduling",
             Self::Lifecycle => "no tools — vestigial since list_containers was removed",
-            Self::Approvals => {
-                "no tools — grants cancel_loose_end's approval-cancel arm (privileged)"
-            }
             Self::Forge => "no tools — vestigial since create_repo was removed",
             Self::Execution => {
                 "run, status — run shell commands via mcp__bash__run / mcp__bash__status"