fix: remove dead code, SSE error handling, bounded dedup maps

- Remove unused mustParseDuration from main.go
- Replace http.Error calls after SSE headers with plain returns;
  skip bad packets instead of killing the stream on marshal error
- Change processedPackets/seenPackets from boolean to timestamp values
  and prune entries older than 24h on each packet to prevent unbounded
  memory growth in long-running sessions

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

web/src/store/slices/aggregatorSlice.ts

@@ -72,8 +72,8 @@ interface AggregatorState {
   channels: Record<string, ChannelData>;
   messages: Record<string, TextMessage[]>;
   selectedNodeId?: number;
-  // Track already processed packet IDs to prevent duplicates
-  processedPackets: Record<string, boolean>;
+  // Track already processed packet IDs to prevent duplicates (value = unix timestamp)
+  processedPackets: Record<string, number>;
 }
 
 const initialState: AggregatorState = {
@@ -108,11 +108,19 @@ const processPacket = (state: AggregatorState, packet: Packet) => {
   const nodeIdHex = `!${nodeId.toString(16).toLowerCase()}`;
   const packetKey = `${nodeIdHex}_${data.id}`;
 
+  // Prune processed packets older than 24 hours
+  const cutoff = timestamp - 86400;
+  for (const key of Object.keys(state.processedPackets)) {
+    if (state.processedPackets[key] < cutoff) {
+      delete state.processedPackets[key];
+    }
+  }
+
   // Check if we've already processed this packet
   const isNewPacket = !state.processedPackets[packetKey];
 
-  // Always mark this packet as processed
-  state.processedPackets[packetKey] = true;
+  // Always mark this packet as processed with its timestamp
+  state.processedPackets[packetKey] = timestamp;
 
   // Update gateway data
   // Handle both cases:

web/src/store/slices/packetSlice.ts

@@ -10,7 +10,7 @@ interface PacketState {
   error: string | null;
   streamPaused: boolean;
   bufferedPackets: Packet[]; // Holds packets received while paused
-  seenPackets: Record<string, boolean>; // Tracks already seen packet IDs to prevent duplicates
+  seenPackets: Record<string, number>; // Tracks already seen packet IDs (value = unix timestamp) to prevent duplicates
 }
 
 const initialState: PacketState = {
@@ -19,7 +19,7 @@ const initialState: PacketState = {
   error: null,
   streamPaused: false,
   bufferedPackets: [],
-  seenPackets: {}, // Empty object to track seen packets
+  seenPackets: {}, // Empty object to track seen packets (key → unix timestamp)
 };
 
 const packetSlice = createSlice({
@@ -40,7 +40,8 @@ const packetSlice = createSlice({
           const packetKey = `${nodeId}_${packet.data.id}`;
 
           if (!state.seenPackets[packetKey]) {
-            state.seenPackets[packetKey] = true;
+            const ts = packet.data.rxTime || Math.floor(Date.now() / 1000);
+            state.seenPackets[packetKey] = ts;
             uniquePackets.push(packet);
           }
         } else {
@@ -65,6 +66,16 @@ const packetSlice = createSlice({
         return;
       }
 
+      const now = packet.data.rxTime || Math.floor(Date.now() / 1000);
+
+      // Prune seen packets older than 24 hours
+      const cutoff = now - 86400;
+      for (const key of Object.keys(state.seenPackets)) {
+        if (state.seenPackets[key] < cutoff) {
+          delete state.seenPackets[key];
+        }
+      }
+
       // Create a Meshtastic node ID format
       const nodeId = `!${packet.data.from.toString(16).toLowerCase()}`;
       const packetKey = `${nodeId}_${packet.data.id}`;
@@ -75,8 +86,8 @@ const packetSlice = createSlice({
         return;
       }
 
-      // Mark this packet as seen
-      state.seenPackets[packetKey] = true;
+      // Mark this packet as seen with its timestamp
+      state.seenPackets[packetKey] = now;
 
       if (state.streamPaused) {
         // When paused, add to buffer instead of main list