Begin portable TORCH fleet rewrite

src/kernel/git.mjs

@@ -0,0 +1,57 @@
+import { execFileSync } from 'node:child_process';
+import { realpathSync } from 'node:fs';
+import { basename } from 'node:path';
+import { TorchError } from './errors.mjs';
+
+function git(cwd, args, { optional = false } = {}) {
+  try {
+    return execFileSync('git', ['-C', cwd, ...args], {
+      encoding: 'utf8',
+      stdio: ['ignore', 'pipe', 'pipe'],
+    }).trim();
+  } catch (error) {
+    if (optional) return '';
+    throw new TorchError(`Git command failed: git ${args.join(' ')}`, {
+      code: 'GIT_COMMAND_FAILED',
+      details: error.stderr?.toString().trim() || undefined,
+    });
+  }
+}
+
+export function inspectRepository(cwd = process.cwd()) {
+  const rootText = git(cwd, ['rev-parse', '--show-toplevel'], { optional: true });
+  if (!rootText) {
+    throw new TorchError(`Not a Git repository: ${cwd}`, { code: 'NOT_GIT_REPOSITORY' });
+  }
+
+  const root = realpathSync(rootText);
+  const branch = git(root, ['branch', '--show-current'], { optional: true }) || null;
+  const head = git(root, ['rev-parse', 'HEAD'], { optional: true }) || null;
+  const initialCommit = head
+    ? git(root, ['rev-list', '--max-parents=0', 'HEAD'], { optional: true }).split('\n')[0] || null
+    : null;
+  const status = git(root, ['status', '--porcelain=v1', '--untracked-files=all'], { optional: true });
+  const remotesText = git(root, ['remote', '-v'], { optional: true });
+  const remotes = remotesText
+    ? remotesText.split('\n').map((line) => {
+      const [name, url, kindText = ''] = line.split(/\s+/);
+      return { name, url, kind: kindText.replace(/[()]/g, '') || 'unknown' };
+    })
+    : [];
+
+  return {
+    root,
+    name: basename(root),
+    branch,
+    head,
+    initialCommit,
+    dirtyEntries: status ? status.split('\n') : [],
+    remotes,
+    canonicalRemote: remotes.find((remote) => remote.name === 'origin' && remote.kind === 'fetch') ?? null,
+  };
+}
+
+export function trackedFiles(root) {
+  const output = git(root, ['ls-files', '-z'], { optional: true });
+  return output ? output.split('\0').filter(Boolean) : [];
+}