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/changes/archive/2026-05-19-tool-instances/.pi-map.md

@@ -0,0 +1,21 @@
+# openspec/changes/archive/2026-05-19-tool-instances
+dir: openspec/changes/archive/2026-05-19-tool-instances
+
+index: openspec/changes/archive/2026-05-19-tool-instances/.pi-map.index.md
+
+## role
+Design and planning documents for a Docker-based development tool instance management system with persistent repository-linked sessions.
+## files
+- design.md | Design document specifying a Docker-based tool instance system for launching and managing development environments per repository with lifecycle management and frontend integration. | dep: Docker, Docker Compose, SQLAlchemy/Base, React/useAtom, AppShell, GitRepository, ToolType, Project, User
+- proposal.md | Proposes a system for managing Docker-based development tool instances with persistent sessions linked to repositories | dep: Docker Compose, Docker API, GitRepository, ToolType, database
+- tasks.md | Project task tracking document for implementing Docker-based tool instance management with backend API, frontend UI, and lifecycle operations | dep: FastAPI, SQLAlchemy, Alembic, Docker, React/TypeScript, Jotai, docker-compose
+## arch
+Document-driven specification architecture using markdown-based design docs (design.md, proposal.md, tasks.md) to define a containerized tool instance system with backend API, frontend UI, and lifecycle management before implementation.
+## tags
+docker, design, tool, document, instance, system, managing, development
+## symbols
+-
+## workflows
+-
+## dirty
+-