docs(bluecraft-agentic-docs): refine documentation structure terminology and patterns

Update skill definition and templates to use "references" instead of "routing"
throughout, clarify the root AGENTS.md as the entry document for agent-docs, and
add explicit linking patterns guidance. Improve template wording to emphasize
directional, explicit references and minimal reference depth.

- Rename and expand linking patterns reference
- Update SKILL.md trigger conditions and core rules
- Refine child doc template compatibility note
- Update refactor checklist to focus on reference depth
- Simplify root AGENTS.md template structure

skills/bluecraft-agentic-docs/references/agent-docs-linking-patterns.md

@@ -0,0 +1,56 @@
+# `agent-docs` Linking Patterns
+
+## Preferred Patterns
+
+### Root -> Topic Docs
+
+Use when the repository has a small set of clearly separate instruction topics.
+
+```md
+# Read Required `agent-docs` Before Editing
+
+- Read and follow `agent-docs/topic-a.md` when ...
+- Read and follow `agent-docs/topic-b.md` when ...
+```
+
+### Root -> Project Doc -> Leaf Docs
+
+Use when one project-specific document should explicitly reference several closely related leaf docs.
+
+```md
+AGENTS.md
+  -> agent-docs/project-guidelines.md
+      -> agent-docs/topic-a.md
+      -> agent-docs/topic-b.md
+```
+
+Use this only when the intermediate layer reduces ambiguity or repeated cross-reference text.
+
+### Root -> Subproject `agent-docs/`
+
+Use in monorepos when a subproject has its own scoped instruction set.
+
+```md
+AGENTS.md
+  -> apps/docs/agent-docs/project-guidelines.md
+  -> services/api/agent-docs/backend-guidelines.md
+```
+
+Common rules stay in the root `AGENTS.md`. Subproject-specific rules stay near the subproject they govern.
+
+## Anti-Patterns
+
+- Root file linking to every leaf doc in a large tree without grouping
+- Child docs that are never reachable from the root
+- Topic-specific rules stored in the root file without a reference reason
+- Extra index files that only restate links without adding scope or decision logic
+- Moving rules out of the root file without leaving an explicit reference to the new child file
+- Keeping monorepo-wide and subproject-specific constraints mixed together in the same root section when they can be separated cleanly
+
+## Explicit Reference Rule
+
+Parent documents should point to the child documents that refine them.
+
+If a child document exists and is active, there must be an explicit reference path from the root `AGENTS.md` to that document.
+
+The root `AGENTS.md` should list only the next `agent-docs` documents that are actually needed. Do not add unnecessary next-step links just for completeness.