agent permissions: one set, tool groups included, set at agent creation

mara on #5170: "dont split caps and perms. its all perms. / dont include
the now empty tool groups / nothing set -> default / also add perms to
agent creation screen".

- hive-sh4re: one `Permission` enum (messaging, meta, inbox, execution,
  web_tools, manage_root_agent) replaces `ToolGroup` and `Capability`;
  `lifecycle`/`forge` are gone. `Permission::default_for` is the default
  for an agent the swarm sets nothing for.
- The record is `{ "permissions": [...] }`. Missing key, unset field or
  no successful read yet = default; `[]` = none; a failed read after a
  good one keeps the last value.
- hive-agent reads its own key every 10s and builds each turn's --tools,
  --allowedTools and MCP config (rewritten before every turn) from it;
  the subagent daemon reads it on each start/continue. Agents get a
  read-only grant on their own key.
- hive-c0re restarts an agent only when its manage_root_agent changes.
  The import now merges meta/capabilities.json and meta/tool-groups.json
  into one list per agent and deletes both; the "import pending, don't
  read" decision is `ImportOutcome::read_allowed`, table-tested.
- swarm-controller: `GET /api/permissions` (names + default) and an
  optional `permissions` on `POST /api/agents`, stored before the job is
  queued. swarm-ui's create-agent form gets a permissions field.
- Deleted: HIVE_TOOL_GROUPS and its forward to the subagent daemon,
  tool_groups.rs, ruth's tool-group seed, the permissions rebuild job
  (PermPayload/WritePermFile/perm_change), the dashboard permissions tab
  and its stale-entries panel.

Part of #5170.

hive-c0re/src/job_queue/model.rs

@@ -1,7 +1,7 @@
 //! Data model for the generic job-DAG queue: the node kinds — the primitive
-//! operations — and what each one carries. The `State` / `PermPayload` wire
-//! enums live in `hive_host_sock::jobs` (they travel on the host admin
-//! socket) and are re-exported here for the queue's internal use. The graph
+//! operations — and what each one carries. The `State` wire
+//! enum lives in `hive_host_sock::jobs` (it travels on the host admin
+//! socket) and is re-exported here for the queue's internal use. The graph
 //! itself is served through `hive_jobq_wire`'s generic projection — there is
 //! no second, typed view of it any more.
 //!
@@ -12,7 +12,7 @@
 //! job is exactly the nodes it declared. See `docs/scheduler/coordinator.md::Job queue`
 //! for the full design.
 
-pub use hive_host_sock::jobs::{PermPayload, State};
+pub use hive_host_sock::jobs::State;
 use serde::Serialize;
 
 /// The primitive operations — each kind maps to one executor fn in
@@ -98,12 +98,10 @@ pub enum NodeKind {
     PauseDrain { agent: String },
     /// `set_nspawn_flags` + `set_resource_limits` + daemon-reload.
     WriteDropin { agent: String },
-    /// Commit `tool-groups.json` per its `payload`.
-    WritePermFile { agent: String, payload: PermPayload },
     /// 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 a rebuild / perm-change: emit this agent's `Rebuilt`
+    /// Tail node of a rebuild: 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
     /// report).
@@ -185,7 +183,6 @@ impl NodeKind {
             | NodeKind::PauseSignal { agent }
             | NodeKind::PauseDrain { agent }
             | NodeKind::WriteDropin { agent }
-            | NodeKind::WritePermFile { agent, .. }
             | NodeKind::AgentWindow { agent }
             | NodeKind::EmitRebuilt { agent, .. }
             | NodeKind::SetWanted { agent, .. } => agent,