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).

.opencode/skills/openspec-archive-change/.pi-map.index.md

@@ -0,0 +1,19 @@
+# .opencode/skills/openspec-archive-change (index)
+dir: .opencode/skills/openspec-archive-change
+
+## role
+Provides a skill definition for archiving completed changes in an experimental workflow using the openspec CLI.
+## parent
+index: .opencode/skills/.pi-map.index.md
+map: .opencode/skills/.pi-map.md
+## children
+-
+## files
+- SKILL.md
+## links
+index: .opencode/skills/openspec-archive-change/.pi-map.index.md
+map: .opencode/skills/openspec-archive-change/.pi-map.md
+## workflows
+-
+## dirty
+-

.opencode/skills/openspec-archive-change/.pi-map.md

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+# .opencode/skills/openspec-archive-change
+dir: .opencode/skills/openspec-archive-change
+
+index: .opencode/skills/openspec-archive-change/.pi-map.index.md
+
+## role
+Provides a skill definition for archiving completed changes in an experimental workflow using the openspec CLI.
+## files
+- SKILL.md | Defines a skill for archiving completed changes in an experimental workflow using the openspec CLI. | dep: openspec CLI, AskUserQuestion tool, Task tool, file system (mkdir, mv, read), JSON parsing
+## arch
+Single-file skill definition using markdown-based skill documentation pattern with CLI tool integration.
+## tags
+skill, defines, archiving, completed, changes, experimental, workflow, openspec
+## symbols
+-
+## workflows
+-
+## dirty
+-