fix(hooks): shared spawn-bin helper — all three AskUserQuestion hooks were inert on Windows

The plan-tune hooks resolved bin scripts via new URL(import.meta.url).pathname
(which doubles the drive letter on Windows: /C:/C:/...) and spawnSync'd
extensionless bash scripts directly (unrunnable without a shell association)
— so question logging, preferences, and the error fallback all silently
no-op'd on Windows, and /plan-tune collected no data. A single spawn-bin.ts
helper now owns bin resolution (fileURLToPath) and win32 bash routing for
every hook, with static tripwires so a future hook can't reintroduce the
raw pattern. This is the one Windows-spawn idiom for hook code.

Fixes #2356.

Contributed by @rafassousa (PR #2504; supersedes PR #2399 by @chuchu2781).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

hosts/claude/hooks/question-preference-hook.ts

@@ -43,7 +43,7 @@
 import * as fs from 'fs';
 import * as path from 'path';
 import * as os from 'os';
-import { spawnSync } from 'child_process';
+import { runBin, repoRoot } from './spawn-bin';
 import { isConductor } from '../../../lib/is-conductor';
 import { classifyQuestion } from '../../../scripts/one-way-doors';
 
@@ -240,9 +240,7 @@ function loadRegistry(): Record<string, RegistryEntry> {
   registryCache = {};
   try {
     // Hook lives at hosts/claude/hooks/; registry at scripts/question-registry.ts
-    const here = path.dirname(new URL(import.meta.url).pathname);
-    const repoRoot = path.resolve(here, '..', '..', '..');
-    const regPath = path.join(repoRoot, 'scripts', 'question-registry.ts');
+    const regPath = path.join(repoRoot(), 'scripts', 'question-registry.ts');
     if (!fs.existsSync(regPath)) return registryCache;
     const src = fs.readFileSync(regPath, 'utf-8');
     // Cheap regex extraction so the hook doesn't need to import the TS file
@@ -334,9 +332,6 @@ function logAutoDecided(
   cwd: string | undefined,
 ): void {
   try {
-    const here = path.dirname(new URL(import.meta.url).pathname);
-    const repoRoot = path.resolve(here, '..', '..', '..');
-    const bin = path.join(repoRoot, 'bin', 'gstack-question-log');
     const payload: Record<string, unknown> = {
       skill: 'unknown',
       question_id: questionId,
@@ -348,7 +343,7 @@ function logAutoDecided(
       session_id: sessionId?.slice(0, 64),
       tool_use_id: toolUseId?.slice(0, 128),
     };
-    spawnSync(bin, [JSON.stringify(payload)], {
+    runBin('gstack-question-log', [JSON.stringify(payload)], {
       encoding: 'utf-8',
       stdio: ['ignore', 'pipe', 'pipe'],
       timeout: 3000,