refactor(HAI-116): rename kb to hai across all packages, CLI, and docs

- Rename npm packages from @kb/* to @hai/* and update all workspace references
- Rename CLI binary from kb to hai and config directory from .kb to .hai
- Update dashboard UI branding, titles, and references from kb to hai
- Update all test files, CI workflows, and documentation to reflect new naming
- Run comprehensive grep verification to ensure no stale kb references remain

.gitignore

@@ -6,6 +6,7 @@ dist/
 *.tsbuildinfo
 
 # hai runtime (local board state — don't commit)
+.kb/
 .hai/
 
 # Taskplane runtime artifacts