Add WiFi v2 API endpoints for dual-mode scanning

- Add v2 capabilities, quick scan, deep scan, and status endpoints
- Add v2 networks, clients, probes, and channels endpoints
- Add v2 SSE stream, export (CSV/JSON), and baseline management
- Add recommendation_rank field to ChannelRecommendation model

The frontend was already wired up to call these v2 endpoints but they
were missing from the backend. This completes the WiFi module v2 API.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

utils/wifi/models.py

@@ -441,6 +441,7 @@ class ChannelRecommendation:
     score: float  # Lower is better
     reason: str
     is_dfs: bool = False
+    recommendation_rank: Optional[int] = None
 
     def to_dict(self) -> dict:
         """Convert to dictionary for JSON serialization."""
@@ -450,6 +451,7 @@ class ChannelRecommendation:
             'score': round(self.score, 3),
             'reason': self.reason,
             'is_dfs': self.is_dfs,
+            'rank': self.recommendation_rank,
         }