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/specs/project-management/.pi-map.md

@@ -0,0 +1,19 @@
+# openspec/specs/project-management
+dir: openspec/specs/project-management
+
+index: openspec/specs/project-management/.pi-map.index.md
+
+## role
+Defines requirements for a project management system that groups repositories with ownership, access control, and SSH key management.
+## files
+- spec.md | Defines requirements for a project management system that groups repositories with ownership, access control, and SSH key management. | dep: Project, User, GitRepository, SSHKey, git-repo, ssh-keys
+## arch
+Specification-driven design using markdown-based requirements documentation.
+## tags
+project, management, ssh, spec, defines, requirements, system, groups
+## symbols
+-
+## workflows
+-
+## dirty
+-