feat: Tick-based staggered polling for all sources

Both MeshviewSource and MeshMonitorDataSource now use tick-based
staggered polling instead of batch-every-5-minutes:

MeshviewSource (30s ticks):
- Packets: every tick (30s)
- Nodes: every 4 ticks (2 min)
- Stats/Edges: every 6 ticks (3 min)
- Traceroutes: every 10 ticks (5 min)

MeshMonitorDataSource (30s ticks):
- Packets: every 2 ticks (60s)
- Nodes/Telemetry: every 4 ticks (2 min)
- Traceroutes/Channels/Network/Topology: every 10 ticks (5 min)
- Solar: every 20 ticks (10 min)

Features:
- Source health status (avg_response_ms, tick_count, backed_off)
- Source coverage analysis (unique vs shared nodes)
- Tier 1 DATA SOURCES section shows all source health
- Node detail shows source visibility
- Incremental packets and telemetry with dedup
- Rate limit detection (429) with backoff
- Consecutive error exponential backoff
- polite_mode config option for shared instances

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

meshai/config.py

@@ -145,7 +145,8 @@ class MeshMonitorConfig:
     enabled: bool = False
     url: str = ""  # e.g., http://100.64.0.11:3333
     inject_into_prompt: bool = True  # Tell LLM about MeshMonitor commands
-    refresh_interval: int = 300  # Seconds between refreshes
+    refresh_interval: int = 30     # Tick interval in seconds (default 30)
+    polite_mode: bool = False      # Reduces polling frequency for shared instances  # Seconds between refreshes
 
 
 @dataclass
@@ -165,7 +166,8 @@ class MeshSourceConfig:
     type: str = ""  # "meshview" or "meshmonitor"
     url: str = ""
     api_token: str = ""  # MeshMonitor only, supports ${ENV_VAR}
-    refresh_interval: int = 300
+    refresh_interval: int = 30     # Tick interval in seconds (default 30)
+    polite_mode: bool = False      # Reduces polling frequency for shared instances
     enabled: bool = True