ci: add flake8 lint workflow; fix unused imports and f-string issues

Removes unused datetime/re imports (F401). Removes f prefix from
2 f-strings with no placeholders (F541). Fixes trailing whitespace
and missing newline (W291/W292). Config ignores style-only rules.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

ceph_osd_analyzer.py

@@ -17,9 +17,6 @@ import subprocess
 import sys
 import argparse
 from collections import defaultdict
-from datetime import datetime
-import re
-
 DEBUG = False
 
 class Colors:
@@ -396,8 +393,8 @@ def calculate_resilience_score(osd_data, host_name, all_hosts_data, osd_tree):
     host_class_counts = {}
     for host_node in [n for n in osd_tree['nodes'] if n['type'] == 'host']:
         h_name = host_node['name']
-        host_osds = [osd_tree['nodes'][i] for i in range(len(osd_tree['nodes'])) 
-                     if osd_tree['nodes'][i].get('id') in host_node.get('children', []) 
+        host_osds = [osd_tree['nodes'][i] for i in range(len(osd_tree['nodes']))
+                     if osd_tree['nodes'][i].get('id') in host_node.get('children', [])
                      and osd_tree['nodes'][i].get('type') == 'osd']
         
         host_class_counts[h_name] = {
@@ -586,12 +583,12 @@ def analyze_cluster():
                 print(f"    - {issue}")
         
         if candidate['capacity_factors']:
-            print(f"  Capacity Optimization:")
+            print("  Capacity Optimization:")
             for factor in candidate['capacity_factors'][:2]:
                 print(f"    • {factor}")
         
         if candidate['resilience_factors']:
-            print(f"  Host Distribution:")
+            print("  Host Distribution:")
             for factor in candidate['resilience_factors'][:2]:
                 print(f"    • {factor}")
         
@@ -622,9 +619,10 @@ def analyze_cluster():
                 print(f"  Issues: {candidate['health_issues'][0]}")
             print()
 
+
 if __name__ == "__main__":
     parser = argparse.ArgumentParser(description='Analyze Ceph OSDs for replacement candidates across entire cluster')
-    parser.add_argument('--class', dest='device_class', choices=['hdd', 'nvme'], 
+    parser.add_argument('--class', dest='device_class', choices=['hdd', 'nvme'],
                         help='Filter by device class')
     parser.add_argument('--min-size', type=float, default=0,
                         help='Minimum OSD size in TB to consider')
@@ -645,4 +643,4 @@ if __name__ == "__main__":
         print(f"{Colors.RED}Error: {e}{Colors.END}")
         import traceback
         traceback.print_exc()
-        sys.exit(1)
+        sys.exit(1)