fix(usage): improve MiniMax coding-plan usage parsing for model_remains array

- Pick the chat model entry (MiniMax-M*) from model_remains instead of using the first BFS candidate, which could be a speech/video/image model with total_count=0.
- Derive window label from start_time/end_time timestamps when window_hours/window_minutes fields are absent; fixes the hardcoded 5h default for 4h windows.
- Include model name in plan label so users can distinguish free-tier coding-plan quota from paid API balance.

Closes #52335

src/infra/provider-usage.fetch.minimax.ts

@@ -267,6 +267,23 @@ function collectUsageCandidates(root: Record<string, unknown>): Record<string, u
   return candidates.map((candidate) => candidate.record);
 }
 
+function deriveWindowLabelFromTimestamps(record: Record<string, unknown>): string | undefined {
+  const startTime = parseEpoch(record.start_time ?? record.startTime);
+  const endTime = parseEpoch(record.end_time ?? record.endTime);
+  if (startTime && endTime && endTime > startTime) {
+    const durationHours = (endTime - startTime) / 3_600_000;
+    if (durationHours >= 1 && Number.isFinite(durationHours)) {
+      const rounded = Math.round(durationHours);
+      return `${rounded}h`;
+    }
+    const durationMinutes = Math.round((endTime - startTime) / 60_000);
+    if (durationMinutes > 0) {
+      return `${durationMinutes}m`;
+    }
+  }
+  return undefined;
+}
+
 function deriveWindowLabel(payload: Record<string, unknown>): string {
   const hours = pickNumber(payload, WINDOW_HOUR_KEYS);
   if (hours && Number.isFinite(hours)) {
@@ -276,6 +293,10 @@ function deriveWindowLabel(payload: Record<string, unknown>): string {
   if (minutes && Number.isFinite(minutes)) {
     return `${minutes}m`;
   }
+  const fromTimestamps = deriveWindowLabelFromTimestamps(payload);
+  if (fromTimestamps) {
+    return fromTimestamps;
+  }
   return "5h";
 }
 
@@ -315,6 +336,40 @@ function deriveUsedPercent(payload: Record<string, unknown>): number | null {
   return null;
 }
 
+/**
+ * When the API returns a `model_remains` array, prefer the entry whose
+ * `model_name` matches a chat/text model (e.g. "MiniMax-M*") and that has
+ * a non-zero `current_interval_total_count`.  Models with total_count === 0
+ * (speech, video, image) are not relevant to the coding-plan budget.
+ */
+function pickChatModelRemains(
+  modelRemains: unknown[],
+): Record<string, unknown> | undefined {
+  const records = modelRemains.filter(isRecord);
+  if (records.length === 0) {
+    return undefined;
+  }
+
+  const chatRecord = records.find((r) => {
+    const name = typeof r.model_name === "string" ? r.model_name : "";
+    const total = parseFiniteNumber(r.current_interval_total_count);
+    return (
+      (name.toLowerCase().startsWith("minimax-m") || name === "MiniMax-M*") &&
+      total !== undefined &&
+      total > 0
+    );
+  });
+
+  if (chatRecord) {
+    return chatRecord;
+  }
+
+  return records.find((r) => {
+    const total = parseFiniteNumber(r.current_interval_total_count);
+    return total !== undefined && total > 0;
+  });
+}
+
 export async function fetchMinimaxUsage(
   apiKey: string,
   timeoutMs: number,
@@ -362,8 +417,15 @@ export async function fetchMinimaxUsage(
   }
 
   const payload = isRecord(data.data) ? data.data : data;
-  const candidates = collectUsageCandidates(payload);
-  let usageRecord: Record<string, unknown> = payload;
+
+  // Handle the model_remains array structure returned by the coding-plan
+  // endpoint.  Pick the chat-model entry so that speech/video/image quotas
+  // (which often have total_count === 0) don't shadow the relevant budget.
+  const modelRemains = Array.isArray(payload.model_remains) ? payload.model_remains : null;
+  const chatRemains = modelRemains ? pickChatModelRemains(modelRemains) : undefined;
+
+  const candidates = collectUsageCandidates(chatRemains ?? payload);
+  let usageRecord: Record<string, unknown> = chatRemains ?? payload;
   let usedPercent: number | null = null;
   for (const candidate of candidates) {
     const candidatePercent = deriveUsedPercent(candidate);
@@ -374,7 +436,7 @@ export async function fetchMinimaxUsage(
     }
   }
   if (usedPercent === null) {
-    usedPercent = deriveUsedPercent(payload);
+    usedPercent = deriveUsedPercent(chatRemains ?? payload);
   }
   if (usedPercent === null) {
     return {
@@ -398,10 +460,19 @@ export async function fetchMinimaxUsage(
     },
   ];
 
+  const modelName =
+    chatRemains && typeof chatRemains.model_name === "string"
+      ? chatRemains.model_name
+      : undefined;
+  const plan =
+    pickString(usageRecord, PLAN_KEYS) ??
+    pickString(payload, PLAN_KEYS) ??
+    (modelName ? `Coding Plan · ${modelName}` : undefined);
+
   return {
     provider: "minimax",
     displayName: PROVIDER_LABELS.minimax,
     windows,
-    plan: pickString(usageRecord, PLAN_KEYS) ?? pickString(payload, PLAN_KEYS),
+    plan,
   };
 }