feat(newos4): the script runner runs scripts — control flow, variables, globs, redirects, stdin

MAINT-021 and MAINT-017, executed from .hermes/plans/2026-10-27_145500-newos4-script-runner.md.

- shell.js: new block parser (_parseBlocks) and executor (_runInstructions/_runSimple/_runCommand/
  _dispatchOne). `for`/`while`/`if` bodies now run, including one-line `if [ -f x ]; then y; fi`.
  Variables expand through _expandVars ($VAR, ${VAR}, $?, single quotes literal), globs expand
  through _expandGlobs (unquoted args only, per-command), and `>`/`>>` capture the command's output
  into the VFS instead of being passed to the command as text.
- shell.js: a script never answers an unknown command by calling the AI any more. It prints
  `script:<path>:<line>: <cmd>: command not found` and sets $? — the AI fallback stays for typing.
- shell.js: unclosed blocks and bad `for` headers surface as `Script <path> failed: …` (the parse
  used to sit outside the try, so a bad script crashed the runner).
- shell.js: interactive path gets the same treatment — prompt globbing and `echo hi > /f` now work.
  Cause of the asymmetry: the two code paths had separate dispatch.
- shell.js: `_isPipeAware` no longer injects the __pipebuf__ file into wc (it reads _pipeInput), and
  the module registers itself with a versioned URL and calls its own init() — registerModule() does
  not call init(), so the executeCommand wrapper was never installed from the boot bundle.
- module-fs.js: wc/head/tail/grep read piped stdin when no file operand is given; `cat` accepts
  several operands (`cat *.txt`); `ls <file>` names the file instead of printing "(empty)".
- main.html: shell.js removed from the extension list — it is already inside
  critical-ext-bundle.js, and loading it twice produced two ShellModule instances that could
  disagree about their version.

Verification:
- test-shell-script.js 27 asserts (parser, variables, globs, executor, redirect, command-not-found,
  one-line if, parse error). RED on HEAD: `TypeError: shell._parseBlocks is not a function`.
- test-shell-stdin.js 16 asserts (added by a subagent): wc -l/-c, head -n, tail -n over stdin, and
  the file-argument path unchanged.
- Suite 18/18 files; maintain --fix "node tests 18/18 pass".
- Live on v4.6.115, through the real executeCommand:
  `ls /n*.txt` -> /n1.txt · `cat /n*.txt` -> one|two · `echo hi > /r.txt` then `cat /r.txt` -> hi ·
  `cat /probe.txt | wc -l` -> 3 (bare, no __pipebuf__) ·
  `script /run.sh` -> item 1 / item 2 / item 3 / exists / command not found, exit 1, no AI routing.

0 files changed, 0 insertions, 0 deletions