fix: go to file in big non-git folders; linear reply handling

- find/git producers piped into head tolerate SIGPIPE, so hitting a cap no
  longer fails the command (and lets ttyd truncate its reply).
- fs-find outside git skips build/cache folders and caps at 10000.
- runCommand checks completion on the stream's tail instead of re-decoding
  the whole reply on every frame.

Refs #37

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/src/files.js

@@ -406,7 +406,7 @@ export class FilesPane {
 
   async loadFileList() {
     if (this.fileList && Date.now() - this.fileList.at < 60000 && this.fileList.session === this.session) return this.fileList.items;
-    const list = parseListOutput(await runCommand(['--fs-find', this.session], 20000));
+    const list = parseListOutput(await runCommand(['--fs-find', this.session], 45000));
     const items = list.files.map((path) => {
       const name = base(path);
       const [icon] = iconFor(name);