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-c0re/src/job_queue/model.rs

@@ -15,8 +15,6 @@
 pub use hive_host_sock::jobs::{PermPayload, State};
 use serde::Serialize;
 
-use hive_jobq::TerminalState;
-
 /// The primitive operations — each kind maps to one executor fn in
 /// `exec.rs`, a thin wrapper over existing `lifecycle.rs` / `meta.rs`
 /// code. Concurrency is gated by two resource classes (see
@@ -61,7 +59,7 @@ pub enum NodeKind {
     /// `remove_dir_all`) plus its state and applied dirs.
     PurgeState { agent: String },
     /// The post-destroy bookkeeping tail.
-    DestroyBookkeeping { agent: String, purge: bool },
+    DestroyBookkeeping { agent: String },
     /// Meta flake lock bump. `sweep = false`: `meta::lock_update` with this
     /// node's own `inputs`; `sweep = true`: `meta::lock_update_hyperhive`
     /// (boot sweep, `inputs` empty). See _Notable collapses_ for how the
@@ -105,17 +103,6 @@ pub enum NodeKind {
     /// Group root of a rebuild subtree — the **brace**, scoped to one
     /// agent. Why braces exist and what they cost: _Braces_.
     AgentWindow { agent: String },
-    /// Tail node of an approval-carrying DAG (a meta-inputs update): resolve
-    /// the approval row from how the work ended.
-    ResolveApproval {
-        approval_id: i64,
-        /// Which outcome this node reports. A template emits **one per
-        /// outcome**, each edged to accept only that one, so exactly one is
-        /// ever runnable. The `Cancelled` one is also the node
-        /// [`super::JobQueue::cancel`] spares, since its edge is the only
-        /// one that accepts a dropped dependency.
-        outcome: TerminalState,
-    },
     /// Tail node of a rebuild / perm-change: emit this agent's `Rebuilt`
     /// manager event. One node per agent *and* per outcome; no cancel
     /// variant (a cancelled DAG never ran, so there is no rebuild to
@@ -175,8 +162,8 @@ impl hive_jobq_wire::WireNode for NodeKind {
 
 impl NodeKind {
     /// The agent this node targets, or `""` for agentless kinds
-    /// ([`NodeKind::MetaLock`] on the `hyperhive` pseudo-agent,
-    /// [`NodeKind::ResolveApproval`] which acts on an approval row).
+    /// ([`NodeKind::MetaLock`] on the `hyperhive` pseudo-agent, and the
+    /// swarm-wide sweeps and pulls).
     #[must_use]
     pub fn agent(&self) -> &str {
         match self {
@@ -203,7 +190,6 @@ impl NodeKind {
             | NodeKind::EmitRebuilt { agent, .. }
             | NodeKind::SetWanted { agent, .. } => agent,
             NodeKind::MetaLock { .. }
-            | NodeKind::ResolveApproval { .. }
             | NodeKind::ForgeSweep
             | NodeKind::MatrixSweep
             | NodeKind::KnowledgePull