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/dashboard/mod.rs

@@ -37,7 +37,6 @@ use crate::lifecycle;
         (name = "lifecycle_ops", description = "agent container lifecycle: rebuild/restart/start/stop/pause/limits"),
         (name = "meta_inputs", description = "bulk flake-input update for the meta flake"),
         (name = "misc_api", description = "mark-all-read, compose, spawn-request, hive stats"),
-        (name = "permissions", description = "tool-group assignment for agents"),
         (name = "rebuild_queue", description = "rebuild-queue cancel"),
         (name = "state_files", description = "proxied reads of allow-listed per-agent state files"),
         (name = "state_snapshot", description = "cold-load dashboard snapshot"),
@@ -56,7 +55,6 @@ mod health;
 mod lifecycle_ops;
 mod meta_inputs;
 mod misc_api;
-pub(crate) mod permissions;
 mod rebuild_queue;
 mod state_files;
 mod state_snapshot;
@@ -124,11 +122,6 @@ fn app(coord: Arc<Coordinator>) -> axum::Router {
         .routes(routes!(build_logs::get_build_logs_agent))
         .routes(routes!(build_logs::get_build_log_full))
         .routes(routes!(build_logs::get_build_log_raw))
-        .routes(routes!(permissions::get_tool_groups))
-        .routes(routes!(permissions::post_tool_groups))
-        .routes(routes!(permissions::post_permissions))
-        .routes(routes!(permissions::get_stale_permissions))
-        .routes(routes!(permissions::delete_agent_permissions))
         .routes(routes!(rebuild_queue::post_rebuild_queue_cancel))
         .routes(routes!(lifecycle_ops::post_destroy))
         .routes(routes!(lifecycle_ops::post_kill))
@@ -376,11 +369,6 @@ mod router_build_probe {
             .routes(routes!(build_logs::get_build_logs_agent))
             .routes(routes!(build_logs::get_build_log_full))
             .routes(routes!(build_logs::get_build_log_raw))
-            .routes(routes!(permissions::get_tool_groups))
-            .routes(routes!(permissions::post_tool_groups))
-            .routes(routes!(permissions::post_permissions))
-            .routes(routes!(permissions::get_stale_permissions))
-            .routes(routes!(permissions::delete_agent_permissions))
             .routes(routes!(rebuild_queue::post_rebuild_queue_cancel))
             .routes(routes!(lifecycle_ops::post_destroy))
             .routes(routes!(lifecycle_ops::post_kill))