feat(using-wiki-graph): thin trigger skill for the wiki-graph MCP [v0.1.0]

skills/using-wiki-graph/SKILL.md — triggers on relational/structural wiki
questions («что связывает X и Y», path/neighbors/backlinks/orphans), routes to
mcp__wiki-graph__* instead of single-page reads (the 0%-recall failure mode).
Precondition: dense corpora only (modulair yes, sparse meta-wiki no).

hermes/mapping.yaml: registered as `pending` (intended auto/mcp, mirrors
using-vds-ops) — NOT promoted to auto; promotion gated on a
using-wiki-graph-test-trigger behavioral audit (instrument-touch).

Installed scoped via scripts/install.sh. Closes [wiki-graph-skill].
NOTE: build-hermes currently red on pre-existing unmapped skill 'meta-host-routing' (not this change).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

hermes/mapping.yaml

@@ -154,6 +154,13 @@ skills:
       category: mcp
     reason: "Calls mcp__vds-ops__* tools (read-only, but touches infrastructure). Behavioral audit via using-vds-ops-test-trigger required before promotion to auto."
 
+  using-wiki-graph:
+    mode: pending
+    intended:
+      mode: auto
+      category: mcp
+    reason: "Calls mcp__wiki-graph__* tools (read-only, parses a .wiki/ corpus server-side). Behavioral audit via using-wiki-graph-test-trigger required before promotion to auto."
+
   session-handoff:
     mode: pending
     intended: