docs(#1014): update stale root→ruth references in conventions, approvals, agent-hierarchy

docs/agent-hierarchy.md

@@ -104,16 +104,14 @@ which axis the post-milestone version reads each special-case along:
 
 ### A — naming + bootstrap
 
-- `MANAGER_AGENT = "root"` (broker recipient name),
-  `MANAGER_NAME = "root"` (logical name, state-dir key), and
-  `MANAGER_CONTAINER = "h-root"` (nixos-container name). The `h-`
-  prefix makes the manager consistent with all sub-agents and lets
-  `lifecycle::list()` use a single `starts_with("h-")` filter.
-  Existing `root` containers are renamed to `h-root` by migration
-  phase 5 in `migrate.rs` (idempotent, marker-guarded).
+- `MANAGER_AGENT = "ruth"` (broker recipient name),
+  `MANAGER_NAME = "ruth"` (logical name, state-dir key), and
+  `MANAGER_CONTAINER = "h-ruth"` (nixos-container name); the `h-`
+  prefix lets `lifecycle::list()` use a single `starts_with("h-")`
+  filter.
 - `auto_update::ensure_manager` runs at hive-c0re boot and spawns
-  `h-root` if missing. **Topology**: root has no parent, so
-  hive-c0re itself owns its lifecycle (no parent to delegate to).
+  `h-ruth` if missing. **Topology**: ruth defaults to root-level (no
+  parent); hive-c0re handles the bootstrap lifecycle directly.
 
 ### B — wire-protocol privileges
 
@@ -175,7 +173,6 @@ read.
 
 ### F — drive-by checks across c0re
 
-(`grep -n MANAGER_AGENT` produced ~28 hits)
 
 - `loose_ends.rs`: manager sees hive-wide loose-ends, sub-agents only
   their own. **Topology** — every agent sees its own + its
@@ -238,9 +235,8 @@ repos they're working on.
 meta-flake's per-agent flake.nix wrapper). For the manager unit
 that means a hardcoded `HIVE_LABEL` env value:
 
-- `HIVE_LABEL = "root"` — logical agent name; matches what `meta.rs`
-  injects at deploy time. (The nixos-container is `h-root`, but the
-  harness identifies itself by logical name.)
+- `HIVE_LABEL = "ruth"` — logical agent name; matches what `meta.rs`
+  injects at deploy time.
 
 Real deploys never read these — `meta::render_flake` overrides them
 via the generated wrapper. They exist so the manager