docs: address mara review on #1936

- Drop the redundant 'including the root/bootstrap container' /
  'sub-agents + root' enumerations in the port-range + state-dir
  uniformity statements — 'every agent' / 'all agents' is enough (and
  calling out '+ root' reintroduces the special-case framing).
- Stop describing the root agent's privileged (manager-flavour) socket
  as a current thing (it's being removed): drop the conventions.md
  capability clause, the network.md per-agent-privileged-socket list
  entry, and the persistence.md /run/hyperhive/manager/mcp.sock
  runtime-dir bullet.

docs/gotchas.md

@@ -96,7 +96,7 @@ across `destroy`/recreate (`--purge` wipes them).
 ## Persistent notes dir per agent
 
 `/var/lib/hyperhive/agents/<name>/state/` bind-mounts to
-`/agents/<name>/state` (RW; uniform for all agents — sub-agents + root).
+`/agents/<name>/state` (RW; uniform for all agents).
 The harness exposes the same path
 via `$HYPERHIVE_STATE_DIR`. System prompts tell agents to keep
 durable knowledge here (`notes.md`, anything else). The harness also
@@ -111,8 +111,8 @@ collision rate gets meaningful; at 2–3 agents you can still get
 unlucky. Operator resolves a collision by renaming the offending
 agent (different hash → different port) and rebuilding. No state
 file, no probing, no port-allocation drift — the value is
-reproducible from just the name. Every agent — including the
-root/bootstrap container — hashes into 8100..8999 via the same FNV-1a; dashboard
+reproducible from just the name. Every agent hashes into
+8100..8999 via the same FNV-1a; dashboard
 at `cfg.dashboardPort` (default 7000).
 
 ## Restart races on TCP bind