feat: upload to external services clublog qrz

frontend/src/components/BandMap.tsx

@@ -160,13 +160,47 @@ export function BandMap({ band, spots, spotStatus, currentFreqHz, onSpotClick, o
       filtered.push(s);
     }
     filtered.sort((a, b) => b.freq_khz - a.freq_khz);
+
+    // Desired pill-CENTRE Y for each spot = its true frequency's Y.
+    const desired = filtered.map(
+      (s) => TOP_PAD + (1 - (s.freq_khz - lo) / span) * innerH,
+    );
+
+    // Non-overlapping label placement via isotonic regression (pool-
+    // adjacent-violators). We want centres c_0 ≤ c_1 ≤ … with
+    // c_{i+1} − c_i ≥ PILL_H, minimising the squared displacement from each
+    // label's desired centre. Substituting q_i = c_i − i·PILL_H turns the
+    // gap constraint into "q non-decreasing", which PAVA solves exactly in
+    // one pass. The win over the old greedy push-down: a tight cluster is
+    // centred on its mean, so its labels fan out symmetrically ABOVE and
+    // below the frequency (Log4OM style) instead of all spilling downward.
+    const n = filtered.length;
+    type Block = { sum: number; count: number; start: number };
+    const blocks: Block[] = [];
+    for (let i = 0; i < n; i++) {
+      // e_i = desired_i − i·PILL_H is the target for the substituted q.
+      let cur: Block = { sum: desired[i] - i * PILL_H, count: 1, start: i };
+      while (blocks.length > 0) {
+        const prev = blocks[blocks.length - 1];
+        if (prev.sum / prev.count <= cur.sum / cur.count) break;
+        blocks.pop();
+        cur = { sum: prev.sum + cur.sum, count: prev.count + cur.count, start: prev.start };
+      }
+      blocks.push(cur);
+    }
+    const centers = new Array<number>(n);
+    for (const b of blocks) {
+      const mean = b.sum / b.count; // optimal q for the whole block
+      for (let i = b.start; i < b.start + b.count; i++) centers[i] = mean + i * PILL_H;
+    }
+    // Centres are non-decreasing, so centers[0] is the topmost. Shift the
+    // whole set down by any overflow above the band edge so the first label
+    // isn't clipped (preserves the ≥ PILL_H spacing).
+    const shift = n > 0 ? Math.max(0, TOP_PAD - (centers[0] - PILL_H / 2)) : 0;
+
     const out: Placed[] = [];
-    let prevY = -Infinity;
-    for (const s of filtered) {
-      const fy = TOP_PAD + (1 - (s.freq_khz - lo) / span) * innerH;
-      const ly = Math.max(fy, prevY + PILL_H);
-      out.push({ spot: s, freqY: fy, labelY: ly });
-      prevY = ly;
+    for (let i = 0; i < n; i++) {
+      out.push({ spot: filtered[i], freqY: desired[i], labelY: centers[i] + shift - PILL_H / 2 });
     }
     const lastLabelBottom = out.length ? out[out.length - 1].labelY + PILL_H : 0;
     return {