v0.1.17: UI fixes, Linux improvements, documentation overhaul

UI/UX:
- Fix heartbeat auto-refresh and rate-limiting page
- Add navigation breadcrumbs to settings pages
- New screenshots added

Linux Agent v0.1.17:
- Fix disk detection for multiple mount points
- Improve installer idempotency
- Prevent duplicate registrations

Documentation:
- README rewrite: 538→229 lines, homelab-focused
- Split docs: API.md, CONFIGURATION.md, DEVELOPMENT.md
- Add NOTICE for Apache 2.0 attribution

.gitignore

@@ -14,9 +14,15 @@
 # All documentation goes in docs/ folder (private development)
 docs/
 *.md
+TEST-CLONE.md
 !README.md
 !LICENSE
+!NOTICE
 !.env.example
+!docs/API.md
+!docs/CONFIGURATION.md
+!docs/ARCHITECTURE.md
+!docs/DEVELOPMENT.md
 
 # Test binary, built with `go test -c`
 *.test
@@ -418,6 +424,11 @@ deployment/
 # =============================================================================
 docs/
 *.md
+TEST-CLONE.md
 !README.md
 !LICENSE
-!.env.example
+!.env.example
+!docs/API.md
+!docs/CONFIGURATION.md
+!docs/ARCHITECTURE.md
+!docs/DEVELOPMENT.md