ci: configure and stabilize CI/CD pipeline

- fix runner configuration issues
- correct workflow labels and execution environment
- resolve dependency issues in pipeline (python deps)
- improve reliability of automation runs

migration-validation-framework/docs/architecture.md

@@ -0,0 +1,30 @@
+# Migration Validation Framework Architecture
+
+## Components
+
+- CLI: parses operator commands and coordinates workflows.
+- Collectors: gather mounts, services, and disk usage from target systems.
+- Snapshot files: JSON evidence used as immutable migration checkpoints.
+- Comparator: evaluates drift between before and after snapshots.
+- Reports: stores JSON or HTML output for audit and review.
+
+## Data Flow
+
+```
+Operator
+  -> python3 cli.py collect
+  -> collectors over SSH
+  -> before.json / after.json
+  -> python3 cli.py compare
+  -> diff.json with PASS/FAIL validation
+```
+
+## Validation Flow
+
+```
+before.json -> Comparator -> service checks
+after.json  -> Comparator -> filesystem checks -> validation result
+                         -> mount checks
+```
+
+The framework keeps collection and comparison separate so migration evidence can be reviewed, archived, and replayed without recollecting from production systems.