chore: track .pi-map.md and .pi-map.index.md artifacts

Remove the map files from .gitignore so they are committed as project
navigation artifacts, and also unignore them in the sample fixture.
Regenerate all maps so the committed versions reflect the current source.

openspec/changes/archive/2026-06-11-layered-map-protocol/.pi-map.index.md

@@ -0,0 +1,26 @@
+# openspec/changes/archive/2026-06-11-layered-map-protocol (index)
+dir: openspec/changes/archive/2026-06-11-layered-map-protocol
+
+## role
+Contains archived specification documents for a deprecated layered map protocol that introduced paired navigation artifacts to replace bulk-loading of map files with a tiered directory-level routing system.
+## parent
+index: openspec/changes/archive/.pi-map.index.md
+map: openspec/changes/archive/.pi-map.md
+## children
+-
+## files
+- apply-progress.md
+- archive-report.md
+- design.md
+- proposal.md
+- spec.md
+- sync-report.md
+- tasks.md
+- verify-report.md
+## links
+index: openspec/changes/archive/2026-06-11-layered-map-protocol/.pi-map.index.md
+map: openspec/changes/archive/2026-06-11-layered-map-protocol/.pi-map.md
+## workflows
+-
+## dirty
+-