Fix European trip return heuristic for weekend location tracking

Adjust European short trip heuristic from >3 days to >1 day to correctly
detect when user has returned home from European trips. This fixes the
April 29-30, 2023 case where the location incorrectly showed "Sankt Georg, Hamburg"
instead of "Bristol" when the user was free (no events scheduled) after
the foss-north trip ended on April 27.

The previous logic required more than 3 days to pass before assuming
return home from European countries, but for short European trips by
rail/ferry, users typically return within 1-2 days.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

node_modules/which/bin/node-which

@@ -0,0 +1,52 @@
+#!/usr/bin/env node
+var which = require("../")
+if (process.argv.length < 3)
+  usage()
+
+function usage () {
+  console.error('usage: which [-as] program ...')
+  process.exit(1)
+}
+
+var all = false
+var silent = false
+var dashdash = false
+var args = process.argv.slice(2).filter(function (arg) {
+  if (dashdash || !/^-/.test(arg))
+    return true
+
+  if (arg === '--') {
+    dashdash = true
+    return false
+  }
+
+  var flags = arg.substr(1).split('')
+  for (var f = 0; f < flags.length; f++) {
+    var flag = flags[f]
+    switch (flag) {
+      case 's':
+        silent = true
+        break
+      case 'a':
+        all = true
+        break
+      default:
+        console.error('which: illegal option -- ' + flag)
+        usage()
+    }
+  }
+  return false
+})
+
+process.exit(args.reduce(function (pv, current) {
+  try {
+    var f = which.sync(current, { all: all })
+    if (all)
+      f = f.join('\n')
+    if (!silent)
+      console.log(f)
+    return pv;
+  } catch (e) {
+    return 1;
+  }
+}, 0))