fix(git-commit): cap commit resolution cache with FIFO eviction (#108856)

* fix(git-commit): cap commit resolution cache with FIFO eviction

The module-level cachedGitCommitBySearchDir Map grows without bound.
A 256-entry FIFO cap prevents unbounded memory growth from repeated
lookups across distinct search directories.

* fix(git-commit): use shared LRU cache pruning

---------

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

src/infra/git-commit.test.ts

@@ -288,6 +288,45 @@ describe("git commit resolution", () => {
     expect(readGitCommit.mock.calls.length).toBe(firstCallReads);
   });
 
+  it.each([
+    { name: "successful", result: "abcdef0" },
+    { name: "failed", result: null },
+  ])("bounds $name git probe entries with LRU eviction", async ({ result }) => {
+    const temp = await makeTempDir(`git-commit-${result ? "success" : "failure"}-lru`);
+    const coldDir = path.join(temp, "cold");
+    const hotDir = path.join(temp, "hot");
+    const newestDir = path.join(temp, "newest");
+    const readGitCommit = vi.fn((_searchDir: string, _packageRoot: string | null) => result);
+    const resolve = (cwd: string) =>
+      resolveCommitHash({
+        cwd,
+        env: {},
+        readers: {
+          readGitCommit,
+          readBuildInfoCommit: () => null,
+          readPackageJsonCommit: () => null,
+        },
+      });
+    const callsFor = (cwd: string) =>
+      readGitCommit.mock.calls.filter(([searchDir]) => searchDir === cwd).length;
+
+    expect(resolve(coldDir)).toBe(result);
+    expect(resolve(hotDir)).toBe(result);
+    for (let index = 0; index < 254; index += 1) {
+      expect(resolve(path.join(temp, `filler-${index}`))).toBe(result);
+    }
+
+    expect(resolve(hotDir)).toBe(result);
+    expect(resolve(newestDir)).toBe(result);
+    expect(resolve(newestDir)).toBe(result);
+    expect(resolve(hotDir)).toBe(result);
+    expect(resolve(coldDir)).toBe(result);
+
+    expect(callsFor(newestDir)).toBe(1);
+    expect(callsFor(hotDir)).toBe(1);
+    expect(callsFor(coldDir)).toBe(2);
+  });
+
   it("formats env-provided commit strings consistently", async () => {
     const temp = await makeTempDir("git-commit-env");
     expect(resolveCommitHash({ cwd: temp, env: { GIT_COMMIT: "ABCDEF0123456789" } })).toBe(

src/infra/git-commit.ts

@@ -5,6 +5,7 @@ import path from "node:path";
 import { fileURLToPath } from "node:url";
 import { normalizeLowercaseStringOrEmpty } from "@openclaw/normalization-core/string-coerce";
 import { resolveGitHeadPath } from "./git-root.js";
+import { pruneMapToMaxSize } from "./map-size.js";
 import { resolveOpenClawPackageRootSync } from "./openclaw-root.js";
 
 const formatCommit = (value?: string | null) => {
@@ -23,6 +24,7 @@ const formatCommit = (value?: string | null) => {
 };
 
 const cachedGitCommitBySearchDir = new Map<string, string | null>();
+const GIT_COMMIT_CACHE_LIMIT = 256;
 
 type CommitMetadataReaders = {
   readGitCommit?: (searchDir: string, packageRoot: string | null) => string | null | undefined;
@@ -66,6 +68,7 @@ const safeReadFilePrefix = (filePath: string, limit = 256) => {
 
 const cacheGitCommit = (searchDir: string, commit: string | null) => {
   cachedGitCommitBySearchDir.set(searchDir, commit);
+  pruneMapToMaxSize(cachedGitCommitBySearchDir, GIT_COMMIT_CACHE_LIMIT);
   return commit;
 };
 const resolveGitLookupDepth = (searchDir: string, packageRoot: string | null) => {
@@ -224,7 +227,12 @@ export const resolveCommitHash = (
   }
   const searchDir = resolveCommitSearchDir(options);
   if (cachedGitCommitBySearchDir.has(searchDir)) {
-    return cachedGitCommitBySearchDir.get(searchDir) ?? null;
+    const cached = cachedGitCommitBySearchDir.get(searchDir) ?? null;
+    // Git discovery reads multiple files; keep active directories ahead of cold entries when
+    // the shared insertion-order pruning helper enforces the bound.
+    cachedGitCommitBySearchDir.delete(searchDir);
+    cachedGitCommitBySearchDir.set(searchDir, cached);
+    return cached;
   }
   const packageRoot = resolveOpenClawPackageRootSync({
     cwd: options.cwd,