Sasquatch fast-path: don't dead-end on empty/typos

The local fast-path was stricter than the AI it replaced: a typo like "bangok"
won't substring-match "Bangkok", so the fast-path returned a false "No spots
listed there yet" even though Bangkok has spots.

Two-layer fix:

1. Safety net (most important): if a finder fast-path comes back EMPTY, fall
   through to the AI path instead of rendering "nothing found". The AI normalizes
   spelling and can still find results. Stats/weather always render immediately.
   Net effect: fast when the local match works, correct-always via AI when it
   doesn't — never a false empty.

2. Typo tolerance: findSpots city matching now uses placeMatches() — substring
   OR edit-distance-1 against candidate word tokens (only for queries ≥4 chars,
   so short words can't over-match). So "bangok" matches "Bangkok" on the fast
   path too. Freeform content stays a strict substring check to avoid false hits.

Co-authored-by: shakespeare.diy <assistant@shakespeare.diy>

src/components/SasquatchGuide.tsx

@@ -911,14 +911,30 @@ export function SasquatchGuide({ message, onDismiss }: SasquatchGuideProps) {
               break;
           }
           setCvmConnected(true);
+
+          // If a finder came back EMPTY, don't dead-end the user with "nothing
+          // found" — the local match is stricter than the AI (e.g. a typo like
+          // "bangok" won't substring-match "bangkok"). Fall through to the AI
+          // path, which normalizes spelling and can still find results. Stats &
+          // weather are always meaningful, so they render immediately.
+          const fastCount =
+            fastIntent.tool === 'get_community_stats' || fastIntent.tool === 'get_weather'
+              ? 1
+              : ((fastResult as { count?: number } | undefined)?.count ?? 0);
+
+          if (fastCount > 0 || fastIntent.tool === 'get_community_stats' || fastIntent.tool === 'get_weather') {
+            setStreamingText('');
+            appendMessage({
+              role: 'sasquatch',
+              text: formatLocalResults(fastIntent, fastResult),
+              timestamp: Date.now(),
+              isLive: true,
+            });
+            return;
+          }
+          // Empty → fall through to the AI path for a spelling-tolerant retry.
+          console.info('[Sasquatch] fast-path empty, retrying via AI for typo tolerance');
           setStreamingText('');
-          appendMessage({
-            role: 'sasquatch',
-            text: formatLocalResults(fastIntent, fastResult),
-            timestamp: Date.now(),
-            isLive: true,
-          });
-          return;
         } catch (fastErr) {
           // Relays hiccuped — fall through to the AI path as a backup.
           console.warn('[Sasquatch] fast-path failed, falling back to AI:', fastErr);

src/hooks/useCVMClient.ts

@@ -187,6 +187,43 @@ function normalizeForDedupe(s: string | undefined): string {
   return (s ?? '').toLowerCase().replace(/\s+/g, ' ').trim();
 }
 
+/** Levenshtein edit distance, capped early once it exceeds `max` (cheap). */
+function editDistance(a: string, b: string, max = 2): number {
+  if (Math.abs(a.length - b.length) > max) return max + 1;
+  let prev = Array.from({ length: b.length + 1 }, (_, i) => i);
+  for (let i = 1; i <= a.length; i++) {
+    const curr = [i];
+    let rowMin = i;
+    for (let j = 1; j <= b.length; j++) {
+      const cost = a[i - 1] === b[j - 1] ? 0 : 1;
+      const val = Math.min(prev[j] + 1, curr[j - 1] + 1, prev[j - 1] + cost);
+      curr[j] = val;
+      if (val < rowMin) rowMin = val;
+    }
+    if (rowMin > max) return max + 1; // whole row exceeded budget → bail
+    prev = curr;
+  }
+  return prev[b.length];
+}
+
+/**
+ * Tolerant place match: true if the query appears as a substring of the
+ * candidate, OR (for queries ≥4 chars) is within edit-distance 1 of any word
+ * token in the candidate — so a small typo like "bangok" still matches
+ * "Bangkok, Thailand". Short queries require exact substring to avoid
+ * over-matching (e.g. "la" shouldn't fuzzy-hit half the world).
+ */
+function placeMatches(candidate: string, query: string): boolean {
+  const c = candidate.toLowerCase();
+  const q = query.toLowerCase().trim();
+  if (!q) return false;
+  if (c.includes(q)) return true;
+  if (q.length < 4) return false;
+  return c
+    .split(/[^a-z0-9]+/i)
+    .some((word) => word.length >= 3 && editDistance(word, q, 1) <= 1);
+}
+
 /**
  * Collapse spots that are the SAME real-world spot published as different
  * addressable events — e.g. the same place re-posted under a new `d` identifier
@@ -254,13 +291,15 @@ export function useCVMClient() {
       }
 
       if (params.city) {
-        const q = params.city.toLowerCase();
+        const q = params.city;
         spots = spots.filter(
           (e) =>
-            (getTag(e, 'city') ?? '').toLowerCase().includes(q) ||
-            (getTag(e, 'location') ?? '').toLowerCase().includes(q) ||
-            (getTag(e, 'title') ?? '').toLowerCase().includes(q) ||
-            (e as unknown as { content: string }).content.toLowerCase().includes(q)
+            placeMatches(getTag(e, 'city') ?? '', q) ||
+            placeMatches(getTag(e, 'location') ?? '', q) ||
+            placeMatches(getTag(e, 'title') ?? '', q) ||
+            // Content is freeform prose — keep it a strict substring check so a
+            // fuzzy word deep in a description doesn't cause a false match.
+            (e as unknown as { content: string }).content.toLowerCase().includes(q.toLowerCase())
         );
       }