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).

docs/templates/.pi-map.md

@@ -0,0 +1,21 @@
+# docs/templates
+dir: docs/templates
+
+index: docs/templates/.pi-map.index.md
+
+## role
+Provides standardized markdown templates for consistent documentation of APIs, architecture, and features across the project.
+## files
+- api-endpoint.md | Provides a standardized markdown template for documenting REST API endpoints with sections for authentication, requests, responses, and examples.
+- architecture.md | Provides a markdown template for documenting system architecture with standardized sections for components, data flow, technology stack, and operational considerations.
+- feature-doc.md | Markdown template for documenting software features with standardized sections
+## arch
+Template library pattern using structured markdown files with predefined section conventions to enforce documentation uniformity and reduce authoring overhead.
+## tags
+standardized, markdown, template, documenting, api, sections, architecture, provides
+## symbols
+-
+## workflows
+-
+## dirty
+-