chore: track all project map and index files

Add generated .pi-map.md and .pi-map.index.md files across the repository
so the project navigation maps are shared and versioned. These artifacts
are maintained by project_map_init/patch/validate and must be kept in
sync with source edits.

Note: .cache/ remains ignored (added in previous commit).

openspec/docs/.pi-map.index.md

@@ -0,0 +1,19 @@
+# openspec/docs (index)
+dir: openspec/docs
+
+## role
+End-user documentation for the platform's tool type definition and management capabilities, covering both legacy container-based and modern declarative manifest approaches.
+## parent
+index: openspec/.pi-map.index.md
+map: openspec/.pi-map.md
+## children
+-
+## files
+- tool-workshop-guide.md
+## links
+index: openspec/docs/.pi-map.index.md
+map: openspec/docs/.pi-map.md
+## workflows
+-
+## dirty
+-