feat(polymarket): replace position-based ranking with quality-signal relevance

Polymarket results now rank by text similarity, volume, liquidity, price
movement, and competitive score instead of API return position. Also fixes
pagination (DEPTH_CONFIG now controls page count, not a no-op limit param)
and caps results after re-ranking.

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

fixtures/polymarket_sample.json

@@ -7,6 +7,13 @@
       "active": true,
       "closed": false,
       "updatedAt": "2026-02-24T18:30:00.000Z",
+      "volume24hr": 342000,
+      "volume1wk": 1200000,
+      "volume1mo": 3500000,
+      "volume": 5000000,
+      "liquidity": 2100000,
+      "competitive": 0.92,
+      "commentCount": 15,
       "markets": [
         {
           "id": "mkt-arizona-big12-1",
@@ -32,6 +39,13 @@
       "active": true,
       "closed": false,
       "updatedAt": "2026-02-23T12:00:00.000Z",
+      "volume24hr": 89000,
+      "volume1wk": 400000,
+      "volume1mo": 800000,
+      "volume": 1200000,
+      "liquidity": 450000,
+      "competitive": 0.76,
+      "commentCount": 8,
       "markets": [
         {
           "id": "mkt-arizona-ncaa-1",
@@ -57,6 +71,11 @@
       "active": true,
       "closed": true,
       "updatedAt": "2026-02-20T10:00:00.000Z",
+      "volume24hr": 0,
+      "volume1mo": 0,
+      "liquidity": 0,
+      "competitive": 0,
+      "commentCount": 0,
       "markets": [
         {
           "id": "mkt-resolved-1",
@@ -81,6 +100,13 @@
       "active": true,
       "closed": false,
       "updatedAt": "2026-02-24T20:00:00.000Z",
+      "volume24hr": 150000,
+      "volume1wk": 800000,
+      "volume1mo": 2000000,
+      "volume": 4000000,
+      "liquidity": 1800000,
+      "competitive": 0.99,
+      "commentCount": 22,
       "markets": [
         {
           "id": "mkt-multi-1",
@@ -105,6 +131,11 @@
       "active": true,
       "closed": false,
       "updatedAt": "2026-02-10T00:00:00.000Z",
+      "volume24hr": 0,
+      "volume1mo": 0,
+      "liquidity": 0,
+      "competitive": 0,
+      "commentCount": 0,
       "markets": [
         {
           "id": "mkt-dead-1",
@@ -129,6 +160,11 @@
       "active": true,
       "closed": false,
       "updatedAt": "2026-02-22T08:00:00.000Z",
+      "volume24hr": 5000,
+      "volume1mo": 50000,
+      "liquidity": 30000,
+      "competitive": 0.5,
+      "commentCount": 1,
       "markets": [
         {
           "id": "mkt-malformed-1",
@@ -145,6 +181,37 @@
           "oneMonthPriceChange": 0
         }
       ]
+    },
+    {
+      "id": "evt-tangential",
+      "title": "Will AI regulation pass in 2026?",
+      "slug": "ai-regulation-2026",
+      "active": true,
+      "closed": false,
+      "updatedAt": "2026-02-24T10:00:00.000Z",
+      "volume24hr": 500000,
+      "volume1wk": 2000000,
+      "volume1mo": 8000000,
+      "volume": 15000000,
+      "liquidity": 5000000,
+      "competitive": 0.95,
+      "commentCount": 50,
+      "markets": [
+        {
+          "id": "mkt-tangential-1",
+          "question": "Will AI regulation pass in 2026?",
+          "active": true,
+          "closed": false,
+          "outcomes": "[\"Yes\", \"No\"]",
+          "outcomePrices": "[\"0.30\", \"0.70\"]",
+          "volume": "8000000",
+          "volume24hr": "500000",
+          "liquidity": "5000000",
+          "oneDayPriceChange": -0.02,
+          "oneWeekPriceChange": 0.05,
+          "oneMonthPriceChange": 0.08
+        }
+      ]
     }
   ]
 }