feat(commands): add /models and fix /model listing UX

src/auto-reply/reply/model-selection.ts

@@ -46,6 +46,39 @@ const FUZZY_VARIANT_TOKENS = [
   "nano",
 ];
 
+function boundedLevenshteinDistance(a: string, b: string, maxDistance: number): number | null {
+  if (a === b) return 0;
+  if (!a || !b) return null;
+  const aLen = a.length;
+  const bLen = b.length;
+  if (Math.abs(aLen - bLen) > maxDistance) return null;
+
+  // Standard DP with early exit. O(maxDistance * minLen) in common cases.
+  const prev = new Array<number>(bLen + 1);
+  const curr = new Array<number>(bLen + 1);
+  for (let j = 0; j <= bLen; j++) prev[j] = j;
+
+  for (let i = 1; i <= aLen; i++) {
+    curr[0] = i;
+    let rowMin = curr[0];
+
+    const aChar = a.charCodeAt(i - 1);
+    for (let j = 1; j <= bLen; j++) {
+      const cost = aChar === b.charCodeAt(j - 1) ? 0 : 1;
+      curr[j] = Math.min(prev[j] + 1, curr[j - 1] + 1, prev[j - 1] + cost);
+      if (curr[j] < rowMin) rowMin = curr[j];
+    }
+
+    if (rowMin > maxDistance) return null;
+
+    for (let j = 0; j <= bLen; j++) prev[j] = curr[j] ?? 0;
+  }
+
+  const dist = prev[bLen] ?? null;
+  if (dist == null || dist > maxDistance) return null;
+  return dist;
+}
+
 function scoreFuzzyMatch(params: {
   provider: string;
   model: string;
@@ -94,6 +127,13 @@ function scoreFuzzyMatch(params: {
     includes: 80,
   });
 
+  // Best-effort typo tolerance for common near-misses like "claud" vs "claude".
+  // Bounded to keep this cheap across large model sets.
+  const distModel = boundedLevenshteinDistance(fragment, modelLower, 3);
+  if (distModel != null) {
+    score += (3 - distModel) * 70;
+  }
+
   const aliases = params.aliasIndex.byKey.get(key) ?? [];
   for (const alias of aliases) {
     score += scoreFragment(alias.toLowerCase(), {
@@ -293,17 +333,16 @@ export function resolveModelDirectiveSelection(params: {
     const fragment = params.fragment.trim().toLowerCase();
     if (!fragment) return {};
 
+    const providerFilter = params.provider ? normalizeProviderId(params.provider) : undefined;
+
     const candidates: Array<{ provider: string; model: string }> = [];
     for (const key of allowedModelKeys) {
       const slash = key.indexOf("/");
       if (slash <= 0) continue;
       const provider = normalizeProviderId(key.slice(0, slash));
       const model = key.slice(slash + 1);
-      if (params.provider && provider !== normalizeProviderId(params.provider)) continue;
-      const haystack = `${provider}/${model}`.toLowerCase();
-      if (haystack.includes(fragment) || model.toLowerCase().includes(fragment)) {
-        candidates.push({ provider, model });
-      }
+      if (providerFilter && provider !== providerFilter) continue;
+      candidates.push({ provider, model });
     }
 
     // Also allow partial alias matches when the user didn't specify a provider.
@@ -325,11 +364,6 @@ export function resolveModelDirectiveSelection(params: {
       }
     }
 
-    if (candidates.length === 1) {
-      const match = candidates[0];
-      if (!match) return {};
-      return { selection: buildSelection(match.provider, match.model) };
-    }
     if (candidates.length === 0) return {};
 
     const scored = candidates
@@ -354,8 +388,13 @@ export function resolveModelDirectiveSelection(params: {
         return a.key.localeCompare(b.key);
       });
 
-    const best = scored[0]?.candidate;
-    if (!best) return {};
+    const bestScored = scored[0];
+    const best = bestScored?.candidate;
+    if (!best || !bestScored) return {};
+
+    const minScore = providerFilter ? 90 : 120;
+    if (bestScored.score < minScore) return {};
+
     return { selection: buildSelection(best.provider, best.model) };
   };
 
@@ -369,7 +408,7 @@ export function resolveModelDirectiveSelection(params: {
     const fuzzy = resolveFuzzy({ fragment: rawTrimmed });
     if (fuzzy.selection || fuzzy.error) return fuzzy;
     return {
-      error: `Unrecognized model "${rawTrimmed}". Use /model to list available models.`,
+      error: `Unrecognized model "${rawTrimmed}". Use /models to list providers, or /models <provider> to list models.`,
     };
   }
 
@@ -400,7 +439,7 @@ export function resolveModelDirectiveSelection(params: {
   if (fuzzy.selection || fuzzy.error) return fuzzy;
 
   return {
-    error: `Model "${resolved.ref.provider}/${resolved.ref.model}" is not allowed. Use /model to list available models.`,
+    error: `Model "${resolved.ref.provider}/${resolved.ref.model}" is not allowed. Use /models to list providers, or /models <provider> to list models.`,
   };
 }