fix(usage-bar): cap warnedTemplateOverrides warn-once dedupe cache (#102659)

* fix(usage-bar): cap warnedTemplateOverrides warn-once dedupe cache

Replace unbounded warnedTemplateOverrides Set with createDedupeCache(maxSize=256)
for consistency with the bounded fileCache Map (MAX_CACHED_TEMPLATE_FILES=64)
already present in the same file.

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

* fix(usage-bar): bound invalid-template warnings

Co-authored-by: ZengWen-DT <ceng.wen@xydigit.com>

---------

Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Peter Steinberger <steipete@gmail.com>

src/auto-reply/usage-bar/template.test.ts

@@ -113,6 +113,36 @@ describe("loadUsageBarTemplate", () => {
     expect(loadUsageBarTemplate(path)).toMatchObject(tplB);
   });
 
+  it("bounds invalid-template warnings by least-recently-used path", () => {
+    const dir = tmpDir();
+    const paths = Array.from({ length: 257 }, (_, index) => {
+      const path = join(dir, `bad-${index}.json`);
+      writeFileSync(path, "{ not json");
+      return path;
+    });
+
+    for (const path of paths.slice(0, 256)) {
+      expect(loadUsageBarTemplate(path)).toBe(DEFAULT_USAGE_BAR_TEMPLATE);
+    }
+    expect(warnSpy).toHaveBeenCalledTimes(256);
+
+    // Refresh the oldest warning before overflow so the next key becomes the LRU victim.
+    expect(loadUsageBarTemplate(paths[0])).toBe(DEFAULT_USAGE_BAR_TEMPLATE);
+    expect(warnSpy).toHaveBeenCalledTimes(256);
+
+    expect(loadUsageBarTemplate(paths[256])).toBe(DEFAULT_USAGE_BAR_TEMPLATE);
+    expect(warnSpy).toHaveBeenCalledTimes(257);
+    expect(loadUsageBarTemplate(paths[0])).toBe(DEFAULT_USAGE_BAR_TEMPLATE);
+    expect(warnSpy).toHaveBeenCalledTimes(257);
+
+    expect(loadUsageBarTemplate(paths[1])).toBe(DEFAULT_USAGE_BAR_TEMPLATE);
+    expect(warnSpy).toHaveBeenCalledTimes(258);
+    expect(warnSpy).toHaveBeenLastCalledWith(
+      "configured usage template could not be used; using built-in footer",
+      { source: "file", reason: "invalid-json", path: paths[1] },
+    );
+  });
+
   describe("cache eviction", () => {
     it("evicts the oldest entry and closes its watcher when inserting a new key over the limit", () => {
       const dir = tmpDir();

src/auto-reply/usage-bar/template.ts

@@ -1,6 +1,7 @@
 import { type FSWatcher, readFileSync, watch } from "node:fs";
 import { homedir } from "node:os";
 import { isAbsolute, resolve } from "node:path";
+import { createDedupeCache } from "../../infra/dedupe.js";
 import { createSubsystemLogger } from "../../logging/subsystem.js";
 import { DEFAULT_USAGE_BAR_TEMPLATE } from "./default-template.js";
 import type { UsageBarTemplate } from "./translator.js";
@@ -11,7 +12,13 @@ type CacheEntry = { template: UsageBarTemplate | undefined; watcher?: FSWatcher
 const fileCache = new Map<string, CacheEntry>();
 /** Maximum number of template file paths to cache concurrently. */
 const MAX_CACHED_TEMPLATE_FILES = 64;
-const warnedTemplateOverrides = new Set<string>();
+const MAX_WARNED_TEMPLATE_OVERRIDES = 256;
+// Retain recent warning keys without accumulating every historical config value.
+// LRU eviction intentionally allows old invalid overrides to warn again.
+const warnedTemplateOverrides = createDedupeCache({
+  maxSize: MAX_WARNED_TEMPLATE_OVERRIDES,
+  ttlMs: 0,
+});
 const usageTemplateLog = createSubsystemLogger("usage-template");
 
 function expandPath(p: string): string {
@@ -87,10 +94,9 @@ function getErrorCode(error: unknown): string | undefined {
 
 function warnInvalidUsageTemplate(source: "inline" | "file", reason: string, path?: string): void {
   const key = `${source}:${reason}:${path ?? ""}`;
-  if (warnedTemplateOverrides.has(key)) {
+  if (warnedTemplateOverrides.check(key)) {
     return;
   }
-  warnedTemplateOverrides.add(key);
   usageTemplateLog.warn("configured usage template could not be used; using built-in footer", {
     source,
     reason,